Text zu Datei hinzufügen

Neues Buttondesign
Stapelnachrichtsmodus
Anpassbarer Waitlayer
Eigene MessageBox

ChatController/ChatControlWaitLayer.xaml

@@ -61,7 +61,7 @@
 					<RowDefinition Height="2*" />
 				</Grid.RowDefinitions>
 
-				<Label Content="Daten werden übertragen. Bitte warten..." Foreground="#FF000000" FontSize="12" FontFamily="Microsoft Sans Serif" FontWeight="Normal" HorizontalAlignment="Center" VerticalAlignment="Center" />
+				<Label Content="{Binding DialogText, UpdateSourceTrigger=PropertyChanged}" Foreground="#FF000000" FontSize="12" FontFamily="Microsoft Sans Serif" FontWeight="Normal" HorizontalAlignment="Center" VerticalAlignment="Center" />
 
                 <Grid Grid.Row="1" HorizontalAlignment="Center" VerticalAlignment="Center" Width="40" Height="40" x:Name="bSLogoControl" RenderTransformOrigin="0.5,0.5" Background="#00000000" >
                     <Grid.RenderTransform>

ChatController/ChatControlWaitLayer.xaml.cs

@@ -1,10 +1,38 @@
-namespace ChatController
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+using ChatController.Annotations;
+
+namespace ChatController
 {
-    public partial class ChatControlWaitLayer
+    public partial class ChatControlWaitLayer : INotifyPropertyChanged
     {
-        public ChatControlWaitLayer()
+        private string _DialogText;
+
+        public string DialogText
+        {
+            get => _DialogText;
+            set
+            {
+                _DialogText = value;
+                OnPropertyChanged(nameof(DialogText));
+            }
+        }
+
+        public ChatControlWaitLayer(string dialogText = null)
         {
             InitializeComponent();
+
+            DataContext = this;
+
+            DialogText = dialogText ?? "Daten werden übertragen. Bitte warten...";
+        }
+
+        public event PropertyChangedEventHandler PropertyChanged;
+
+        [NotifyPropertyChangedInvocator]
+        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
+        {
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
         }
     }
 }

ChatController/ChatController.csproj

@@ -68,6 +68,7 @@
     </Compile>
     <Compile Include="Converter\BoolToVisibilityConverter.cs" />
     <Compile Include="Converter\BroadcastCheckBoxVisibilityMultiConverter.cs" />
+    <Compile Include="Converter\OwnChatNullVisibilityConverter.cs" />
     <Compile Include="Converter\StringEmptyToVisibilityConverter.cs" />
     <Compile Include="Converter\StringToBoolConverter.cs" />
     <Compile Include="Converter\UserProfilePictureVisibilityConverter.cs" />
@@ -100,7 +101,10 @@
       <DesignTime>True</DesignTime>
       <DependentUpon>Resource.resx</DependentUpon>
     </Compile>
-    <Compile Include="Utilities\BroadcastMessage.cs" />
+    <Compile Include="OwnChatMessageBox.xaml.cs">
+      <DependentUpon>OwnChatMessageBox.xaml</DependentUpon>
+    </Compile>
+    <Compile Include="Utilities\ChatMessageFileWrapper.cs" />
     <Compile Include="Utilities\BroadcastProgressReportModel.cs" />
     <Compile Include="Utilities\Constants.cs" />
     <Compile Include="Utilities\Extensions\ControlExtensions.cs" />
@@ -130,6 +134,10 @@
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </Page>
+    <Page Include="OwnChatMessageBox.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
   </ItemGroup>
   <ItemGroup>
     <Resource Include="Ressourcen\BeyondsoftChat.jpg" />
@@ -153,6 +161,13 @@
   </ItemGroup>
   <ItemGroup>
     <Content Include="ownchat_favicon.ico" />
+    <Resource Include="Ressourcen\times-solid.png" />
+    <Resource Include="Ressourcen\tasks-solid-inverted.png" />
+    <Resource Include="Ressourcen\tasks-solid.png" />
+    <Resource Include="Ressourcen\paper-plane-solid.png" />
+    <Resource Include="Ressourcen\paperclip-solid.png" />
+    <Resource Include="Ressourcen\smile-regular.png" />
+    <Resource Include="Ressourcen\sync-alt.png" />
     <Resource Include="Ressourcen\TasksSolid.png" />
     <Resource Include="Ressourcen\ownchat_image_placeholder.png" />
     <Resource Include="Ressourcen\warning-exclamation-mark.png" />

ChatController/ChatKlassen/ChatMessage.cs

@@ -70,7 +70,7 @@ namespace ChatController.ChatKlassen
             OriginalImage = originalImage;
             OriginalImageName = imageName;
 
-            if(MessageId == 0 && MessageType == ChatMessageType.Image && logo != null)
+            if(MessageId == 0 && MessageType == ChatMessageType.Image && !(logo is null))
             {
                 PictureSource = logo;
                 PicturePlaceholderHeight = (int) logo.Height;
@@ -81,9 +81,7 @@ namespace ChatController.ChatKlassen
             if(!string.IsNullOrWhiteSpace(thumbnailPath))
             {
                 ThumbnailPlaceholderHeight = Utils.GetHeightFromThumbnailUri(thumbnailPath);
-                Thumbnail = Utils.GetPicturePlaceholder();
+                Utils.DownloadDocumentThumbnail(thumbnailPath, imageSource =>
-
-                Utils.DownloadImageAsync(thumbnailPath, $"group-{groupId}", CacheCategory.Thumbnail, imageSource =>
                 {
                     Thumbnail = imageSource;
                 });
@@ -208,17 +206,7 @@ namespace ChatController.ChatKlassen
 
         public override bool Equals(object obj)
         {
-            if(obj is ChatMessage message)
+            return obj is ChatMessage message && (message.IsSeparator && IsSeparator ? SendTime == message.SendTime : Id.Equals(message.Id) && MessageId.Equals(message.MessageId));
-            {
-                if(message.IsSeparator && IsSeparator)
-                {
-                    return SendTime == message.SendTime;
-                }
-
-                return Id.Equals(message.Id) && MessageId.Equals(message.MessageId);
-            }
-
-            return false;
         }
 
         public override string ToString()

ChatController/ChatKlassen/Contact.cs

@@ -54,14 +54,7 @@ namespace ChatController.ChatKlassen
 
                 var isOwnMessage = rmUserId.HasValue && rmUserId.Value.Equals(userId);
 
-                if (_HasUnreadMessages && !isOwnMessage)
+                _Color = _HasUnreadMessages && !isOwnMessage ? new BrushConverter().ConvertFromString("#FF5A00") as SolidColorBrush : new SolidColorBrush(Colors.Gray);
-                {
-                    _Color = new BrushConverter().ConvertFromString("#ff5e00") as SolidColorBrush;
-                }
-                else
-                {
-                    _Color = new SolidColorBrush(Colors.Gray);
-                }
 
                 OnPropertyChanged(nameof(HasUnreadMessages));
                 OnPropertyChanged(nameof(Color));
@@ -135,22 +128,7 @@ namespace ChatController.ChatKlassen
         {
             if(obj is Contact y)
             {
-                if(ReferenceEquals(this, y))
+                return GroupId == y.GroupId;
-                {
-                    return true;
-                }
-
-                if(GetType() != y.GetType())
-                {
-                    return false;
-                }
-
-                return Name == y.Name &&
-                       IsNewMessage == y.IsNewMessage &&
-                       TimeStamp.Equals(y.TimeStamp) &&
-                       GroupId == y.GroupId &&
-                       UserIdManage == y.UserIdManage &&
-                       IsChatMessageInputGridVisible == y.IsChatMessageInputGridVisible;
             }
 
             return false;
@@ -160,16 +138,21 @@ namespace ChatController.ChatKlassen
         {
             unchecked
             {
-                var hashCode = Name != null ? Name.GetHashCode() : 0;
+                var hashCode = Name?.GetHashCode() ?? 0;
 
                 hashCode = (hashCode * 397) ^ GroupId;
-                hashCode = (hashCode * 397) ^ (UserIdManage != null ? UserIdManage.GetHashCode() : 0);
+                hashCode = (hashCode * 397) ^ (UserIdManage?.GetHashCode() ?? 0);
                 hashCode = (hashCode * 397) ^ IsChatMessageInputGridVisible.GetHashCode();
 
                 return hashCode;
             }
         }
 
+        public override string ToString()
+        {
+            return $"({GroupId}) {Name}";
+        }
+
         public SolidColorBrush AccentColorBrush { get; }
 
         public event PropertyChangedEventHandler PropertyChanged;

ChatController/ChatMainControl.xaml

@@ -11,15 +11,14 @@
              mc:Ignorable="d"
              d:DesignHeight="300" d:DesignWidth="600" 
              Loaded="ChatMainControl_OnLoaded"
-             SnapsToDevicePixels="True" d:DataContext="{d:DesignData ChatMainControl}">
+             SnapsToDevicePixels="True" d:DataContext="{d:DesignData Type=ChatMainControl}">
     <UserControl.Resources>
         <converter:BoolToVisibilityConverter x:Key="BoolToVisibilityConverter" />
         <converter:StringEmptyToVisibilityConverter x:Key="StringEmptyToVisibilityConverter" />
         <converter:UserProfilePictureVisibilityConverter x:Key="UserProfilePictureVisibilityConverter" />
         <converter:BroadcastCheckBoxVisibilityMultiConverter x:Key="BroadcastCheckBoxVisibilityMultiConverter" />
+        <converter:OwnChatNullVisibilityConverter x:Key="OwnChatNullVisibilityConverter" />
         
-
-        <!--<SolidColorBrush x:Key="DarkBackColor" Color="#A9B8C2" />-->
         <SolidColorBrush x:Key="DarkBackColor" Color="#A9B8C2" />
         <SolidColorBrush x:Key="LightBackColor" Color="#F3F3F3" />
 
@@ -49,84 +48,31 @@
             </Setter>
         </Style>
 
-        <Style x:Key="CloseButtonStyle" TargetType="{x:Type Button}">
+        <Style x:Key="OrangeToggleButtonStyle" TargetType="{x:Type ToggleButton}">
-            <Setter Property="MinWidth" Value="0" />
+            <Setter Property="BorderBrush" Value="#FF5A00" />
-            <Setter Property="MinHeight" Value="0" />
+            <Setter Property="Background" Value="#FF5A00" />
-            <Setter Property="Width" Value="Auto" />
+            <Setter Property="Foreground" Value="White"></Setter>
-            <Setter Property="Height" Value="Auto" />
-            <Setter Property="Background" Value="Transparent" />
-            <Setter Property="Focusable" Value="false" />
             <Setter Property="Template">
                 <Setter.Value>
-                    <ControlTemplate TargetType="{x:Type Button}">
+                    <ControlTemplate TargetType="{x:Type ToggleButton}">
-                        <ControlTemplate.Resources>
+                        <Border x:Name="Border" Background="#FF5A00" CornerRadius="5" Padding="5,2">
-                            <Storyboard x:Key="Timeline1">
+                            <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
-                                <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="glow" Storyboard.TargetProperty="(UIElement.Opacity)">
+                        </Border>
-                                    <SplineDoubleKeyFrame KeyTime="00:00:00.3000000" Value="1" />
-                                </DoubleAnimationUsingKeyFrames>
-                                <DoubleAnimation Storyboard.TargetName="border" Storyboard.TargetProperty="(UIElement.RenderTransform).(ScaleTransform.ScaleX)" To="1.3" Duration="0:0:0.2" />
-                                <DoubleAnimation Storyboard.TargetName="border" Storyboard.TargetProperty="(UIElement.RenderTransform).(ScaleTransform.ScaleY)" To="1.3" Duration="0:0:0.2" />
-                            </Storyboard>
-                            <Storyboard x:Key="Timeline2">
-                                <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="glow" Storyboard.TargetProperty="(UIElement.Opacity)">
-                                    <SplineDoubleKeyFrame KeyTime="00:00:00.3000000" Value="0" />
-                                </DoubleAnimationUsingKeyFrames>
-                                <DoubleAnimation Storyboard.TargetName="border" Storyboard.TargetProperty="(UIElement.RenderTransform).(ScaleTransform.ScaleX)" Duration="0:0:0.2" />
-                                <DoubleAnimation Storyboard.TargetName="border" Storyboard.TargetProperty="(UIElement.RenderTransform).(ScaleTransform.ScaleY)" Duration="0:0:0.2" />
-                            </Storyboard>
-                        </ControlTemplate.Resources>
-                        <Grid SnapsToDevicePixels="true" x:Name="grid" MinWidth="20" MinHeight="20">
-                            <Border x:Name="border" BorderBrush="#FF000000" BorderThickness="1,1,1,1" CornerRadius="3,3,3,3" Padding="0,0,0,0" Margin="0,0,0,0">
-                                <Border.Background>
-                                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
-                                        <GradientStop Color="#FF450202" Offset="0" />
-                                        <GradientStop Color="#FFC61A1A" Offset="1" />
-                                    </LinearGradientBrush>
-                                </Border.Background>
-                                <Grid>
-                                    <Grid.RowDefinitions>
-                                        <RowDefinition Height="0.5*" />
-                                        <RowDefinition Height="0.5*" />
-                                    </Grid.RowDefinitions>
-                                    <Border Opacity="0" HorizontalAlignment="Stretch" x:Name="glow" Width="Auto" Grid.RowSpan="2" CornerRadius="3,3,3,3">
-                                        <Border.Background>
-                                            <RadialGradientBrush>
-                                                <RadialGradientBrush.RelativeTransform>
-                                                    <TransformGroup>
-                                                        <ScaleTransform ScaleX="1.702" ScaleY="2.243" />
-                                                        <SkewTransform AngleX="0" AngleY="0" />
-                                                        <RotateTransform Angle="0" />
-                                                        <TranslateTransform X="-0.368" Y="-0.152" />
-                                                    </TransformGroup>
-                                                </RadialGradientBrush.RelativeTransform>
-                                                <GradientStop Color="#B2FFFFFF" Offset="0" />
-                                                <GradientStop Color="#00FF9E9A" Offset="1" />
-                                            </RadialGradientBrush>
-                                        </Border.Background>
-                                    </Border>
-                                    <Border Grid.Row="0" HorizontalAlignment="Stretch" Margin="0,0,0,0" x:Name="shine" Width="Auto" CornerRadius="3,3,0,0">
-                                        <Border.Background>
-                                            <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
-                                                <GradientStop Color="#99FFFFFF" Offset="0" />
-                                                <GradientStop Color="#33FFFFFF" Offset="1" />
-                                            </LinearGradientBrush>
-                                        </Border.Background>
-                                    </Border>
-                                    <TextBlock HorizontalAlignment="Center" VerticalAlignment="Center" FontFamily="Webdings" FontSize="16" Foreground="#FFFFFFFF" TextWrapping="Wrap"
-								           Grid.Row="0" Grid.RowSpan="2">
-									<Run Text="r" />
-                                    </TextBlock>
-                                </Grid>
-                            </Border>
-                        </Grid>
                         <ControlTemplate.Triggers>
                             <Trigger Property="IsMouseOver" Value="True">
-                                <Trigger.EnterActions>
+                                <Setter Property="Background" Value="#FF988F" TargetName="Border" />
-                                    <BeginStoryboard Storyboard="{StaticResource Timeline1}" />
+                            </Trigger>
-                                </Trigger.EnterActions>
+                            <Trigger Property="IsPressed" Value="True">
-                                <Trigger.ExitActions>
+                                <Setter Property="Background" Value="#FF7654" TargetName="Border" />
-                                    <BeginStoryboard x:Name="Timeline2_BeginStoryboard" Storyboard="{StaticResource Timeline2}" />
+                            </Trigger>
-                                </Trigger.ExitActions>
+                            <Trigger Property="IsEnabled" Value="False">
+                                <Setter Property="Background" Value="LightGray" TargetName="Border" />
+                            </Trigger>
+                            <Trigger Property="IsChecked" Value="False">
+                                <Setter Property="Background" Value="#FF5A00" TargetName="Border" />
+                            </Trigger>
+                            <Trigger Property="IsChecked" Value="True">
+                                <Setter Property="Background" Value="#FFFFFF" TargetName="Border" />
                             </Trigger>
                         </ControlTemplate.Triggers>
                     </ControlTemplate>
@@ -171,6 +117,7 @@
                 </Setter.Value>
             </Setter>
         </Style>
+
         <ControlTemplate x:Key="ContactListBoxTemplate" TargetType="{x:Type ListBox}">
             <Border x:Name="Bd" SnapsToDevicePixels="True" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}">
                 <ScrollViewer Focusable="False" Padding="{TemplateBinding Padding}" Style="{StaticResource MainNavigationScrollViewer}" HorizontalScrollBarVisibility="Disabled">
@@ -178,6 +125,7 @@
                 </ScrollViewer>
             </Border>
         </ControlTemplate>
+
         <Style x:Key="ContactListStyle" TargetType="{x:Type ListBox}">
             <Setter Property="Template" Value="{StaticResource ContactListBoxTemplate}" />
         </Style>
@@ -186,12 +134,12 @@
         <Style x:Key="ContactListBoxItemStyle" TargetType="{x:Type ListBoxItem}">
             <Setter Property="HorizontalContentAlignment" Value="{Binding Path=HorizontalContentAlignment, RelativeSource={RelativeSource AncestorLevel=1, AncestorType={x:Type ItemsControl}, Mode=FindAncestor}}" />
             <Setter Property="VerticalContentAlignment" Value="{Binding Path=VerticalContentAlignment, RelativeSource={RelativeSource AncestorLevel=1, AncestorType={x:Type ItemsControl}, Mode=FindAncestor}}" />
-            <Setter Property="Margin" Value="0,0,0,0" />
+            <Setter Property="Margin" Value="0" />
             <Setter Property="Template">
                 <Setter.Value>
                     <ControlTemplate>
                         <Grid>
-                            <Border x:Name="ItemBorder" MinHeight="20" Background="White" BorderThickness="0,0,0,0" BorderBrush="{StaticResource LightBackColor}">
+                            <Border x:Name="ItemBorder" MinHeight="20" Background="White" BorderThickness="0" BorderBrush="{StaticResource LightBackColor}">
                             </Border>
                             <Border x:Name="ItemContent" MinHeight="20">
                                 <Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin="5,3,5,3" OpacityMask="{x:Null}" SnapsToDevicePixels="True">
@@ -231,7 +179,7 @@
                                             <RowDefinition Height="*"/>
                                         </Grid.RowDefinitions>
                                         <TextBlock Text="{Binding Path=Contact.Name, FallbackValue=FirstName}" Foreground="{Binding Path=Contact.AccentColorBrush}" FontSize="16" Margin="1" />
-                                        <TextBlock Text="{Binding Path=Contact.ReceivedMessage.Text}" Grid.Row="1" FontSize="14"  Foreground="{Binding Path=Contact.Color}" Margin="1" />
+                                        <TextBlock Text="{Binding Path=Contact.ReceivedMessage.Text}" Grid.Row="1" FontSize="14" Foreground="{Binding Path=Contact.Color}" Margin="1" />
                                     </Grid>
                                 </Grid>
                             </Border>
@@ -269,8 +217,8 @@
                     </Grid.ColumnDefinitions>
                     <ScrollViewer Grid.Column="1" x:Name="PART_ContentHost" Margin="0,2,0,0" />
                     <Canvas Grid.Column="0" Width="14" Margin="3,4,2,2">
-                        <Ellipse Stroke="#FFA0A0A0" Height="10" Width="10" StrokeThickness="2" Fill="{x:Null}" />
+                        <Ellipse Stroke="#A0A0A0" Height="10" Width="10" StrokeThickness="2" Fill="{x:Null}" />
-                        <Line Fill="#FFFFFFFF" Stretch="Fill" Stroke="#FFA0A0A0" Canvas.Left="6" Canvas.Top="7.4" Y1="0" Y2="5" StrokeThickness="3" X2="4" />
+                        <Line Fill="#FFFFFF" Stretch="Fill" Stroke="#A0A0A0" Canvas.Left="6" Canvas.Top="7.4" Y1="0" Y2="5" StrokeThickness="3" X2="4" />
                     </Canvas>
                 </Grid>
             </Border>
@@ -289,6 +237,9 @@
             <Setter Property="Height" Value="40" />
         </Style>
     </UserControl.Resources>
+
+
+
     <Grid x:Name="RootGrid">
         <Border x:Name="rootBorder" Background="{StaticResource DarkBackColor}" Padding="0" Margin="0" BorderThickness="0">
             <Grid>
@@ -300,7 +251,7 @@
                     <RowDefinition Height="*"/>
                 </Grid.RowDefinitions>
 
-                <Grid Grid.Column="0" Grid.Row="0" >
+                <Grid Grid.Column="0" Grid.Row="0">
                     <Grid.RowDefinitions>
                         <RowDefinition Height="50"/>
                         <RowDefinition Height="*"/>
@@ -319,19 +270,24 @@
                             <ColumnDefinition Width="Auto"/>
                         </Grid.ColumnDefinitions>
 
-                        <StackPanel x:Name="ReloadGruppen" Grid.Row="0" Grid.Column="1" Height="25" HorizontalAlignment="Right" Orientation="Horizontal" VerticalAlignment="Center" Visibility="Visible" Margin="0,0,3,0">
+                        <StackPanel x:Name="ReloadGruppen" Grid.Row="0" Grid.Column="1" Height="25" 
+                                    HorizontalAlignment="Right" Orientation="Horizontal" VerticalAlignment="Center" Visibility="Visible" Margin="0,0,3,0">
                             <Button Background="Transparent" HorizontalAlignment="Right"  BorderThickness="0" 
+                                    Style="{StaticResource OrangeButtonStyle}"
                                     VerticalAlignment="Center" VerticalContentAlignment="Center" Width="25" Height="25" Click="ButtonReloadGruppen_OnClick" >
-                                <Image ToolTip="Gruppen Aktualisieren" Margin="0,0,0,0" Width="20" Height="20" 
+                                <Image ToolTip="Gruppen Aktualisieren" Margin="0,0,0,0" 
-                                       Source="pack://application:,,,/ChatController;component/Ressourcen/SymbolRefresh32.png" RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
+                                       Source="pack://application:,,,/ChatController;component/Ressourcen/sync-alt.png" 
-                            </Button>
+                                       RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
-                            <Button HorizontalAlignment="Right"  Background="Transparent" VerticalAlignment="Center" VerticalContentAlignment="Center"
-                                    Click="BroadcastButton_OnClick" Style="{StaticResource OrangeButtonStyle}" Margin="5,0,0,0">
-                                <Image ToolTip="Nachricht an mehrere Empfänger schicken" Margin="0" Width="20" Height="20" 
-                                       Source="pack://application:,,,/ChatController;component/Ressourcen/TasksSolid.png" RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
                             </Button>
+                            <!-- In toggleButton ändern -->
+                            <ToggleButton HorizontalAlignment="Right" Background="Transparent" VerticalAlignment="Center" VerticalContentAlignment="Center"
+                                    Width="25" Height="25" Style="{StaticResource OrangeToggleButtonStyle}" x:Name="BroadcastToggleButton"
+                                    Click="BroadcastToggleButton_OnClick" Margin="5,0,0,0">
+                                <Image ToolTip="Nachricht an mehrere Empfänger schicken" Margin="0" x:Name="ToggleButtonImage"
+                                       Source="pack://application:,,,/ChatController;component/Ressourcen/tasks-solid.png" 
+                                       RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
+                            </ToggleButton>
                         </StackPanel>
-
                         <TextBox Grid.Column="0" x:Name="Suche" Height="22" HorizontalAlignment="Stretch" Margin="5" TabIndex="0" Template="{DynamicResource SearchTextBoxTemplate}" BorderThickness="0,0,0,0" TextChanged="Suche_OnTextChanged" />
                     </Grid>
                     <!-- endregion Gruppensuche und Gruppenliste aktualisieren -->
@@ -339,19 +295,19 @@
                     <!-- region Kontaktliste -->
                     <Grid Grid.Column="0" Grid.Row="1"  >
                         <Grid.RowDefinitions>
-                            <RowDefinition Height="Auto"/>
                             <RowDefinition Height="*"/>
+                            <RowDefinition Height="Auto"/>
                         </Grid.RowDefinitions>
                         <Grid.ColumnDefinitions>
                             <ColumnDefinition Width="*"/>
                         </Grid.ColumnDefinitions>
-                        <CheckBox Grid.Row="0" Margin="5" x:Name="SelectAllContactsCheckBox" FontSize="16" Content="Alle auswählen" VerticalAlignment="Center" Height="35" 
+                        <ListView x:Name="Clientlist" HorizontalAlignment="Stretch" Grid.Row="0" Grid.Column="0" VerticalAlignment="Stretch" BorderThickness="0" Background="White"
-                                  Click="SelectAllContacts_OnClick"
-                                  Visibility="{Binding Path=Chat.IsInBroadcastMode, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}" />
-                        <ListView x:Name="Clientlist" HorizontalAlignment="Stretch" Grid.Row="1" Grid.Column="0" VerticalAlignment="Stretch" BorderThickness="0" Background="White"
                                   ItemsSource="{Binding ContactList, UpdateSourceTrigger=PropertyChanged}"
                                   ItemContainerStyle="{StaticResource ContactListBoxItemStyle}" SelectionChanged="Clientlist_OnSelectionChanged" Style="{StaticResource ContactListStyle}">
                         </ListView>
+                        <CheckBox Grid.Row="1" Margin="5" x:Name="SelectAllContactsCheckBox" FontSize="16" Content="Alle auswählen" VerticalAlignment="Center"  
+                                  Click="SelectAllContacts_OnClick" VerticalContentAlignment="Center"
+                                  Visibility="{Binding Path=Chat.IsInBroadcastMode, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}" />
                     </Grid>
                     <!-- endregion Kontaktliste -->
                 </Grid>
@@ -366,7 +322,18 @@
                         <RowDefinition Height="Auto"/>
                     </Grid.RowDefinitions>
 
-                    <Grid Grid.Row="0" HorizontalAlignment="Left" Background="Transparent" VerticalAlignment="Center" Height="50" PreviewMouseDown="CurrentContactImage_OnMouseDoubleClick">
+                    <!-- #region Fortschrittsoverlay -->
+                    <StackPanel Grid.Column="0" Grid.Row="0" Grid.RowSpan="3" VerticalAlignment="Center" HorizontalAlignment="Stretch"
+                                Orientation="Vertical" Visibility="{Binding Path=ProgressOverlayVisibility, UpdateSourceTrigger=PropertyChanged}">
+                        <ProgressBar Margin="20, 5" Value="{Binding BroadcastProgressValue, UpdateSourceTrigger=PropertyChanged}" Height="20" />
+                        <Button Content="Abbrechen" Width="75" Style="{StaticResource OrangeButtonStyle}" Height="25" Margin="0, 5"
+                                Click="CancelBroadcastButton_OnClick" />
+                    </StackPanel>
+                    <!-- #endregion Fortschrittsoverlay -->
+
+                    <Grid Grid.Row="0" HorizontalAlignment="Left" Background="Transparent" 
+                          Visibility="{Binding Path=NormalViewVisibility, UpdateSourceTrigger=PropertyChanged}"
+                          VerticalAlignment="Center" Height="50" PreviewMouseDown="CurrentContactImage_OnMouseDoubleClick">
                         <Grid.ColumnDefinitions>
                             <ColumnDefinition Width="50" />
                             <ColumnDefinition Width="*" />
@@ -396,7 +363,7 @@
                              Background="{StaticResource LightBackColor}" 
                              ContextMenuOpening="Chat_OnContextMenuOpening" 
                              Padding="20" 
-                             Visibility="{Binding Path=Chat.IsInBroadcastMode, UpdateSourceTrigger=PropertyChanged, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type chatController:ChatMainControl}}, Converter={StaticResource BoolToVisibilityConverter}}"
+                             Visibility="{Binding Path=ChatListBoxVisibility, UpdateSourceTrigger=PropertyChanged, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type chatController:ChatMainControl}}}"
                              d:DataContext="{d:DesignData ChatMessage}">
                         <ListBox.ItemContainerStyle>
                             <Style TargetType="ListBoxItem">
@@ -458,6 +425,7 @@
                                                 <ColumnDefinition Width="Auto" />
                                             </Grid.ColumnDefinitions>
 
+                                            <!-- #region Fremdes Profilbild in Gruppenchat -->
                                             <Ellipse Grid.Column="0" 
                                                      Margin="2,5,2,2" VerticalAlignment="Top" Width="32" Height="32" RenderOptions.BitmapScalingMode="HighQuality">
                                                 <Ellipse.Fill>
@@ -470,11 +438,15 @@
                                                     </MultiBinding>
                                                 </Ellipse.Visibility>
                                             </Ellipse>
+                                            <!-- #endregion Fremdes Profilbild in Gruppenchat -->
 
-                                            <Separator Grid.Column="0" Grid.ColumnSpan="2" Visibility="{Binding IsSeparator, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}" VerticalContentAlignment="Center" />
+                                            <!-- #region Separator -->
-                                            <Label Content="{Binding SeparatorTimeString}" HorizontalAlignment="Center" Grid.Column="2" Visibility="{Binding IsSeparator, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}" />
+                                            <Separator Grid.Column="0" Grid.ColumnSpan="2" HorizontalAlignment="Stretch" Visibility="{Binding IsSeparator, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}" VerticalContentAlignment="Center" />
-                                            <Separator Grid.Column="3" Grid.ColumnSpan="2" Visibility="{Binding IsSeparator, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}" />
+                                            <Label VerticalAlignment="Center" Content="{Binding SeparatorTimeString}" HorizontalAlignment="Center" Grid.Column="2" Visibility="{Binding IsSeparator, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}" />
+                                            <Separator Grid.Column="3" Grid.ColumnSpan="2" HorizontalAlignment="Stretch" Visibility="{Binding IsSeparator, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}" VerticalContentAlignment="Center" />
+                                            <!-- #endregion Separator -->
 
+                                            <!-- #region DockPanel mit Nachricht und gegebenenfalls Datei -->
                                             <DockPanel Grid.Column="1" Grid.ColumnSpan="3" MinHeight="15" Margin="5" LastChildFill="True" Visibility="{Binding IsSeparator, Converter={StaticResource BoolToVisibilityConverter}}">
                                                 <StackPanel DockPanel.Dock="Bottom" Orientation="Vertical">
                                                     <Image ToolTip="Dokument öffnen" Height="{Binding ThumbnailPlaceholderHeight, UpdateSourceTrigger=PropertyChanged}" Width="150" 
@@ -495,7 +467,9 @@
                                                     <TextBlock Text="{Binding UserTimeStringRight}" MaxWidth="{Binding TimeStringMaxWidth}" FontSize="11"  HorizontalAlignment="Right" TextAlignment="Right" VerticalAlignment="Center" Foreground="{Binding Foreground}" />
                                                 </StackPanel>
                                             </DockPanel>
+                                            <!-- #endregion DockPanel mit Nachricht und gegebenenfalls Datei -->
 
+                                            <!-- #region Eigenes Profilbild in Gruppenchat -->
                                             <Ellipse Grid.Column="4" 
                                                      Margin="2,5,2,2" VerticalAlignment="Top" Width="32" Height="32" RenderOptions.BitmapScalingMode="HighQuality">
                                                 <Ellipse.Fill>
@@ -508,6 +482,7 @@
                                                     </MultiBinding>
                                                 </Ellipse.Visibility>
                                             </Ellipse>
+                                            <!-- #endregion Eigenes Profilbild in Gruppenchat -->
                                         </Grid>
                                     </Border>
                                 </StackPanel>
@@ -515,24 +490,52 @@
                         </ListBox.ItemTemplate>
                     </ListBox>
 
-                    <Grid Grid.Row="1" Grid.Column="0" Visibility="{Binding Path=Chat.IsInBroadcastMode, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}">
+                    <!-- #region Stapelmodus/Textbox-Ansicht -->
-                        <Grid.RowDefinitions>
+                    <ScrollViewer HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto" Grid.Row="1" Grid.Column="0" Visibility="{Binding Path=StapelmodusChatGridVisibility, UpdateSourceTrigger=PropertyChanged}">
-                            <RowDefinition Height="Auto" />
+                        <Grid>
-                            <RowDefinition Height="*" />
+                            <Button Width="25" Height="25" HorizontalAlignment="Right" VerticalAlignment="Top" Margin="5,0,5,5"
-                        </Grid.RowDefinitions>
+                                    ToolTip="Angehängte Datei entfernen" 
-                        <Button Grid.Row="0" Grid.Column="0" Margin="5" Height="20" Width="20" HorizontalAlignment="Right" Style="{DynamicResource CloseButtonStyle}" Click="AbortBroadcastButton_OnClick" />
+                                    Visibility="{Binding Path=RemoveFileFromBroadcastMessageVisibility, UpdateSourceTrigger=PropertyChanged}"
-                        <StackPanel Grid.Row="1" Orientation="Vertical" Margin="5" VerticalAlignment="Center">
+                                    Style="{StaticResource OrangeButtonStyle}" Click="RemoveBroadcastFileAttachmentButton_Click">
-                            <TextBlock Text="{Binding BroadcastInfoText, UpdateSourceTrigger=PropertyChanged}" Foreground="Black"
+                                <Image Source ="pack://application:,,,/ChatController;component/Ressourcen/times-solid.png" 
-                                       HorizontalAlignment="Center" TextWrapping="Wrap" TextAlignment="Center" FontSize="16" Margin="20, 0" />
+                                       RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
-                            <ProgressBar Margin="20, 5" Value="{Binding BroadcastProgressValue, UpdateSourceTrigger=PropertyChanged}" Height="20" />
+                            </Button>
-                            <Image MaxHeight="300" RenderOptions.BitmapScalingMode="HighQuality" 
+                            <StackPanel Orientation="Vertical" Margin="5" VerticalAlignment="Center">
-                                   Source="{Binding Path=BroadcastMessage.BroadcastMessageImageSource, UpdateSourceTrigger=PropertyChanged}" Stretch="Uniform"
+                                <TextBlock Text="{Binding BroadcastInfoText, UpdateSourceTrigger=PropertyChanged}" Foreground="Black"
-                                   />
+                                           HorizontalAlignment="Center" TextWrapping="Wrap" TextAlignment="Center" FontSize="16" Margin="20, 0" />
-                            <Button Content="Abbrechen" Width="75" Style="{StaticResource OrangeButtonStyle}" Height="25" Margin="0, 5"
+                                <Image MaxHeight="300" RenderOptions.BitmapScalingMode="HighQuality" Margin="5"
-                                    Click="CancelBroadcastButton_OnClick" />
+                                       Source="{Binding Path=BroadcastMessageFileWrapper.ChatMessageImageSource, UpdateSourceTrigger=PropertyChanged}" Stretch="Uniform" />
-                        </StackPanel>
+                                <TextBlock Text="{Binding Path=BroadcastMessageFileWrapper.FileName, UpdateSourceTrigger=PropertyChanged}" 
-                    </Grid>
+                                           FontSize="16" HorizontalAlignment="Center" Foreground="Black" />
+                            </StackPanel>
+                        </Grid>
+                    </ScrollViewer>
+                    <!-- #endregion Stapelmodus/Textbox-Ansicht -->
 
+                    <!-- #region Normalmodus/Dateivorschau -->
+                    <Grid Grid.Row="1" Grid.Column="0" Visibility="{Binding Path=FilePreviewGridVisibility, UpdateSourceTrigger=PropertyChanged}">
+                        <ScrollViewer HorizontalScrollBarVisibility="Disabled">
+                            <Grid>
+                                <Button Width="25" Height="25" HorizontalAlignment="Right" VerticalAlignment="Top" Margin="5,0,5,5"
+                                        ToolTip="Angehängte Datei entfernen"
+                                        Style="{StaticResource OrangeButtonStyle}" Click="RemoveFileAttachmentButton_Click">
+                                    <Image Source ="pack://application:,,,/ChatController;component/Ressourcen/times-solid.png" 
+                                           RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
+                                </Button>
+                                <StackPanel Orientation="Vertical" Margin="5" VerticalAlignment="Center">
+                                    <Image MaxHeight="300" RenderOptions.BitmapScalingMode="HighQuality" 
+                                           Source="{Binding Path=ChatMessageFileWrapper.ChatMessageImageSource, UpdateSourceTrigger=PropertyChanged}" Stretch="Uniform" />
+                                    <TextBlock Text="{Binding Path=ChatMessageFileWrapper.FileName, UpdateSourceTrigger=PropertyChanged}" 
+                                               FontSize="16" HorizontalAlignment="Center" Foreground="Black" />
+                                </StackPanel>
+                            </Grid>
+                        </ScrollViewer>
+                    </Grid>
+                    
+                    
+                    <!-- #endregion Normalmodus/Dateivorschau -->
+
+                    <!-- #region Nachrichtentextbox -->
                     <Grid Grid.Row="2" Visibility="{Binding ChatMessageInputGridVisibility}" VerticalAlignment="Stretch" MinHeight="25" MaxHeight="200">
                         <Grid.ColumnDefinitions>
                             <ColumnDefinition Width="*" />
@@ -584,29 +587,47 @@
                             </TextBlock.Resources>
                         </TextBlock>
                         <Button Grid.Column="1" Margin="2" x:Name="MediaButton" Background="Transparent" 
-                                Width="28" Height="28" BorderThickness="0" Padding="2"
+                                Width="25" Height="25" BorderThickness="0" Padding="2"
                                 Visibility="{Binding Chat.IsInBroadcastMode, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource BoolToVisibilityConverter}}"
-                                VerticalAlignment="Bottom" ToolTip="Datei einfügen" Click="MediaButton_OnClick" >
+                                VerticalAlignment="Bottom" ToolTip="Datei einfügen" Click="MediaButton_OnClick" 
-                            <Image Width="22" Height="22" Source='pack://application:,,,/ChatController;component/Ressourcen/paperclip2.png' RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center"/>
+                                Style="{StaticResource OrangeButtonStyle}">
+                            <Image Source='pack://application:,,,/ChatController;component/Ressourcen/paperclip-solid.png' 
+                                   RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center"/>
                         </Button>
-                        <Button Grid.Column="1" Margin="2" Background="Transparent"
+                        <Button Grid.Column="1" Margin="3" Style="{StaticResource OrangeButtonStyle}" Width="25" Height="25"
-                                Width="28" Height="28" BorderThickness="0" Padding="2"
                                 Visibility="{Binding Path=Chat.IsInBroadcastMode, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}"
                                 VerticalAlignment="Bottom" ToolTip="Datei einfügen" Click="AddMediaFileToBroadcastMessage_OnClick">
-                            <Image Width="22" Height="22" Source="pack://application:,,,/ChatController;component/Ressourcen/paperclip2.png" RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
+                            <Image Source='pack://application:,,,/ChatController;component/Ressourcen/paperclip-solid.png' 
+                                   RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
                         </Button>
-                        <Button Grid.Column="2" Width="28" Height="28" BorderThickness="0" 
+                        <!-- Emoji-Button -->
-                                Background="Transparent" x:Name="EmojiButton" Margin="2" Padding="0" 
+                        <Button Grid.Column="2" Width="25" Height="25" x:Name="EmojiButton" 
-                                VerticalAlignment="Bottom" ToolTip="Emoji einfügen" Click="EmojiButton_OnClick">
+                                Margin="3" VerticalAlignment="Bottom" ToolTip="Emoji einfügen" 
-                            <Image Width="24" Height="24" Source='pack://application:,,,/ChatController;component/Ressourcen/glucklicher.png'  RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
+                                Style="{StaticResource OrangeButtonStyle}"
+                                Click="EmojiButton_OnClick">
+                            <Image Source='pack://application:,,,/ChatController;component/Ressourcen/smile-regular.png' 
+                                   RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
                         </Button>
-                        <Button x:Name="SendButton" Height="25" Content="Senden" Margin="3" Grid.Column="3" VerticalAlignment="Bottom" Style="{StaticResource OrangeButtonStyle}"
+                        <!-- Senden Button -->
+                        <Button Height="25" Width="25" Margin="3" Grid.Column="3" VerticalAlignment="Bottom" 
+                                Style="{StaticResource OrangeButtonStyle}"
                                 Visibility="{Binding Chat.IsInBroadcastMode, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource BoolToVisibilityConverter}}"
-                                Click="SendButton_OnClick" IsEnabled="{Binding IsSendButtonEnabled, UpdateSourceTrigger=PropertyChanged}" />
+                                Click="SendButton_OnClick" 
-                        <Button Height="25" Content="Senden" Margin="3" Grid.Column="3" VerticalAlignment="Bottom" Style="{StaticResource OrangeButtonStyle}"
+                                IsEnabled="{Binding IsSendButtonEnabled, UpdateSourceTrigger=PropertyChanged}">
+                            <Image Source="pack://application:,,,/ChatController;component/Ressourcen/paper-plane-solid.png" 
+                                   RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
+                        </Button>
+                        <!-- Broadcast Senden Button -->
+                        <Button Height="25" Width="25" Margin="3" Grid.Column="3" VerticalAlignment="Bottom" 
+                                Style="{StaticResource OrangeButtonStyle}"
                                 Visibility="{Binding Path=Chat.IsInBroadcastMode, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}"
-                                Click="SendBroatcastButton_OnClick" IsEnabled="{Binding IsBroadcastButtonEnabled, UpdateSourceTrigger=PropertyChanged}" />
+                                Click="SendBroatcastButton_OnClick" 
+                                IsEnabled="{Binding IsBroadcastButtonEnabled, UpdateSourceTrigger=PropertyChanged}">
+                            <Image Source="pack://application:,,,/ChatController;component/Ressourcen/paper-plane-solid.png" 
+                                   RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
+                        </Button>
                     </Grid>
+                    <!-- #endregion Nachrichtentextbox -->
                 </Grid>
             </Grid>
         </Border>

ChatController/Converter/BoolToVisibilityConverter.cs

@@ -16,6 +16,11 @@ namespace ChatController.Converter
                     return boolValue ? Visibility.Visible : Visibility.Collapsed;
                 }
 
+                if(parameter is string reverseHiddenString && Equals(reverseHiddenString, "reverse_hidden"))
+                {
+                    return boolValue ? Visibility.Visible : Visibility.Hidden;
+                }
+
                 return boolValue ? Visibility.Collapsed : Visibility.Visible;
             }
 

ChatController/Converter/OwnChatNullVisibilityConverter.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Globalization;
+using System.Windows;
+using System.Windows.Data;
+
+namespace ChatController.Converter
+{
+    public class OwnChatNullVisibilityConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return value is null ? Visibility.Collapsed : Visibility.Visible;
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

ChatController/Converter/UserProfilePictureVisibilityConverter.cs

@@ -9,7 +9,7 @@ namespace ChatController.Converter
     {
         public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
         {
-            if(values != null && values.Length == 2 && values[0] is bool isMyMessage && values[1] is bool isGroupChat)
+            if(!(values is null) && values.Length == 2 && values[0] is bool isMyMessage && values[1] is bool isGroupChat)
             {
                 if(parameter is string test && test == "reverse")
                 {

ChatController/Core/BindableTextBlock.cs

@@ -17,7 +17,7 @@ namespace ChatController.Core
 
         public static void OnPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
         {
-            if(e.NewValue == null)
+            if(e.NewValue is null)
             {
                 return;
             }

ChatController/Core/OwnChatCache.cs

@@ -10,6 +10,38 @@ namespace ChatController.Core
 
         private static readonly object _Lock = new object();
 
+        private ImageSource _DocumentThumbnail;
+        public ImageSource DocumentThumbnail
+        {
+            get => _DocumentThumbnail;
+            set
+            {
+                lock(_Lock)
+                {
+                    if(!(value is null) && _DocumentThumbnail is null)
+                    {
+                        _DocumentThumbnail = value;
+                    }
+                }
+            }
+        }
+
+        private ImageSource _ImagePlaceholder;
+        public ImageSource ImagePlaceholder
+        {
+            get => _ImagePlaceholder;
+            set
+            {
+                lock(_Lock)
+                {
+                    if(!(value is null) && _ImagePlaceholder is null)
+                    {
+                        _ImagePlaceholder = value;
+                    }
+                }
+            }
+        }
+
         // Key-> "group-127" oder "user-938"
         private Dictionary<string, ImageSourceCacheStorage> _ImageSourceCache = new Dictionary<string, ImageSourceCacheStorage>();
 
@@ -41,7 +73,7 @@ namespace ChatController.Core
         {
             lock(_Lock)
             {
-                if(key == null || _ImageSourceCache == null || !_ImageSourceCache.ContainsKey(key))
+                if(key is null || _ImageSourceCache is null || !_ImageSourceCache.ContainsKey(key))
                 {
                     return null;
                 }
@@ -56,7 +88,7 @@ namespace ChatController.Core
         {
             lock(_Lock)
             {
-                if(_ImageSourceCache == null)
+                if(_ImageSourceCache is null)
                 {
                     _ImageSourceCache = new Dictionary<string, ImageSourceCacheStorage>();
                 }
@@ -158,7 +190,7 @@ namespace ChatController.Core
 
         public void SetCachedProfilePicture(ImageSource avatarImageSource, string profilePicturePath)
         {
-            if(avatarImageSource != null && !string.IsNullOrWhiteSpace(profilePicturePath))
+            if(!(avatarImageSource is null) && !string.IsNullOrWhiteSpace(profilePicturePath))
             {
                 ProfilePicturePath = profilePicturePath;
                 _ProfilePicture = new ImageSourceCacheObject(avatarImageSource, CacheCategory.ProfilePicture);
@@ -186,7 +218,7 @@ namespace ChatController.Core
 
         public void AddImageSourceToCachedObjects(ImageSource imageSource, CacheCategory cacheCategory, string name)
         {
-            if(CachedObjects == null)
+            if(CachedObjects is null)
             {
                 CachedObjects = new Dictionary<CacheCategory, Dictionary<string, ImageSourceCacheObject>>();
             }
@@ -206,7 +238,7 @@ namespace ChatController.Core
             }
             else
             {
-                CachedObjects.Add(cacheCategory, new Dictionary<string, ImageSourceCacheObject> {{name, newImageSourceCacheObject } });
+                CachedObjects.Add(cacheCategory, new Dictionary<string, ImageSourceCacheObject> { {name, newImageSourceCacheObject } });
             }
         }
     }

ChatController/Data/OwnChatApi.cs

@@ -85,7 +85,7 @@ namespace ChatController.Data
                 
                 using (var dataStream = response.GetResponseStream())
                 {
-                    if(dataStream == null)
+                    if(dataStream is null)
                     {
                         return serverResponse;
                     }

ChatController/HauptKlassen/Chat.cs

@@ -4,6 +4,7 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.ComponentModel;
+using System.Diagnostics;
 using System.Drawing;
 using System.Drawing.Imaging;
 using System.IO;
@@ -76,7 +77,7 @@ namespace ChatController.HauptKlassen
         {
             try
             {
-                if(certificate == null || chain == null)
+                if(certificate is null || chain is null)
                 {
                     return false;
                 }
@@ -224,7 +225,7 @@ namespace ChatController.HauptKlassen
             var span = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
             var timespan = Convert.ToInt64(span.TotalSeconds);
 
-            if (_UserMessages != null && _UserMessages.Response.Messages.Length > 0)
+            if (!(_UserMessages is null) && _UserMessages.Response.Messages.Length > 0)
             {
                 timespan = _UserMessages.Response.Messages.First().Created_At;
             }
@@ -354,9 +355,12 @@ namespace ChatController.HauptKlassen
                 var time = DateTime.Now;
 
                 var chatMessage = new ChatMessage(pGroupId, 0, ChatDaten.LoggedInUser.Response.User.UserName, pMessage, time, true, 0, null, null, null, null, null, ChatMessageType.Message, ChatDaten.LoggedInUser.Response.User.Oid);
-                result.Add(chatMessage);
 
-                return AddSeparators(result);
+                result = AddSeparators(new List<ChatMessage> {previousMessage, chatMessage});
+
+                result.Remove(previousMessage);
+
+                return result;
             }
             catch (Exception exception)
             {
@@ -366,95 +370,6 @@ namespace ChatController.HauptKlassen
             return result;
         }
 
-        // ToDo: Funktioniert nicht mit der Version von RestSharp, die mit .NET Version 4.5 kompatibel ist
-        public void SendMessageAsync(string message, long groupId)
-        {
-            try
-            {
-                var url = ChatDaten.ServerUrl + Constants.SendMessageUrl;
-                var requestBody = $"{HttpUtility.UrlEncode("groupid")}={HttpUtility.UrlEncode(groupId.ToString())}&{HttpUtility.UrlEncode("text")}={HttpUtility.UrlEncode(message)}";
-                var client = new RestClient(url);
-                var request = new RestRequest(Method.POST);
-
-                request.AddHeader(Constants.ContentTypeKey, Constants.MultipartContentTypeValue);
-                request.AddParameter(Constants.Token, ChatDaten.AuthToken);
-                request.AddParameter(Constants.CustomerId, ChatDaten.Kundennummer);
-
-                request.AddParameter(Constants.MultipartContentTypeValue, requestBody, ParameterType.RequestBody);
-
-                client.PostAsync(request, (response, handle) =>
-                {
-
-                });
-
-                /*
-                 *
-                    multiPartContent.Add(new StringContent(groupId.ToString()), "groupid");
-                    multiPartContent.Add(new StringContent(message), "text");
-                    
-                    //wegen Kontent nachschauen 
-                    httpRequest.Content = multiPartContent;
-
-                    httpRequest.Headers.Add("Token", ChatDaten.AuthToken);
-                    httpRequest.Headers.Add("CustomerID", ChatDaten.Kundennummer);
-
-                    ---------------------------------------------------------------------------------------------------------------------------------------------------
-
-                    var url = _BaseUrl + Constants.LoginWithChatCodeUrl;
-                    var requestBody = $"{HttpUtility.UrlEncode("username")}={HttpUtility.UrlEncode(_UserName)}&{HttpUtility.UrlEncode("password")}={HttpUtility.UrlEncode(_Password)}&{HttpUtility.UrlEncode("chatcode")}={HttpUtility.UrlEncode(_ChatCode)}";
-
-                    var client = new RestClient(url);
-                    var request = new RestRequest(Method.POST);
-
-                    request.AddHeader(Constants.ContentTypeKey, Constants.FormUrlEncodedContentTypeValue);
-                    request.AddParameter(Constants.CustomerId, _Tenant, ParameterType.HttpHeader);
-                    request.AddParameter(Constants.FormUrlEncodedContentTypeValue, requestBody, ParameterType.RequestBody);
-
-                    client.PostAsync(request, (response, handle) =>
-                    {
-                        Debug.WriteLine(response.Content);
-
-                        var connectionData = JsonConvert.DeserializeObject<UserDaten>(response.Content);
-
-                        if (connectionData.Success)
-                        {
-                            _AuthToken = connectionData.Response.User.Token;
-                            _UserId = connectionData.Response.User.Oid;
-
-                            Utils.AuthToken = _AuthToken;
-                            Utils.Tenant = _Tenant;
-
-                            _LoggedInUser = connectionData;
-
-                            callback?.Invoke(true);
-                        }
-                        else
-                        {
-                            var errorMessage = string.Empty;
-
-                            if (connectionData.Error?.ChatCodeFailed != null)
-                            {
-                                errorMessage = $"Fehler: {connectionData.Error.ChatCodeFailed[0]}\nBitte überprüfen Sie die Anmeldeinformationen.";
-                            }
-                            else if (connectionData.Error?.LoginFailed != null)
-                            {
-                                errorMessage = $"Fehler: {connectionData.Error.LoginFailed[0]}\nBitte überprüfen Sie die Anmeldeinformationen.";
-                            }
-
-                            if (!string.IsNullOrWhiteSpace(errorMessage))
-                            {
-                                exceptionCallback?.Invoke(errorMessage);
-                            }
-                        }
-                    });
-                 */
-            }
-            catch(Exception exception)
-            {
-                MessageBox.Show(exception.Message, "Fehler", MessageBoxButton.OK);
-            }
-        }
-
         public async Task SendMessage(string message, long groupId)
         {
             try
@@ -474,7 +389,7 @@ namespace ChatController.HauptKlassen
                     httpRequest.Headers.Add("CustomerID", ChatDaten.Kundennummer);
 
                     var httpClient = new HttpClient();
-                    await httpClient.SendAsync(httpRequest, CancellationToken.None).ConfigureAwait(false);
+                    await httpClient.SendAsync(httpRequest, CancellationToken.None);
                 }
             }
             catch (Exception exception)
@@ -503,7 +418,7 @@ namespace ChatController.HauptKlassen
             }
         }
 
-        public List<ChatMessage> AddNewFile(string pathToScaledFile, string originalFilePath, long groupId, ChatMessage previousMessage)
+        public List<ChatMessage> AddNewFile(string pathToScaledFile, string originalFilePath, long groupId, ChatMessage previousMessage, string chatBoxText)
         {
             var result = new List<ChatMessage>();
 
@@ -514,77 +429,94 @@ namespace ChatController.HauptKlassen
                     return result;
                 }
 
-                var latestMessage = _UserMessages.Response.Messages.Last();
+                var messageId = 0;
-
+                var userName = ChatDaten.LoggedInUser.Response.User.UserName;
                 var sendTime = DateTime.Now;
+                var fileName = Path.GetFileName(pathToScaledFile);
+                var imageFile = GetImageFile(pathToScaledFile, out var fileSize);
+                var isImage = Constants.ImageFileExtensions.Contains(Path.GetExtension(pathToScaledFile).ToUpperInvariant());
+                var messageText = string.IsNullOrWhiteSpace(chatBoxText) ? fileName : chatBoxText;
+                var filePath = isImage ? null : pathToScaledFile;
+                var originalImage = isImage ? pathToScaledFile : null;
+                var imageName = isImage ? fileName : null;
+                var linkToThumbnail = isImage ? null : $"{ChatDaten.ServerUrl}/document.png";
+                var logo = isImage ? imageFile : null;
+                var chatMessageType = isImage ? ChatMessageType.Image : ChatMessageType.Document;
+                var senderId = ChatDaten.LoggedInUser.Response.User.Oid;
 
-                if (Constants.ImageFileExtensions.Contains(Path.GetExtension(pathToScaledFile).ToUpperInvariant()))
+                var chatMessage = new ChatMessage(groupId, messageId, userName, messageText, sendTime, true, fileSize, filePath, originalImage, imageName, linkToThumbnail, logo, chatMessageType, senderId);
-                {
-                    byte[] file;
-                    using (Stream reader = File.OpenRead(pathToScaledFile))
-                    {
-                        file = Utils.ReadFully(reader);
-                    }
-                    
-                    using(var memoryStream = new MemoryStream(file))
-                    {
-                        var image = Image.FromStream(memoryStream);
 
-                        using (var bitmap = new Bitmap(image))
+                result = AddSeparators(new List<ChatMessage> { previousMessage, chatMessage });
-                        {
-                            using (var stream = new MemoryStream())
-                            {
-                                short orient = 0;
-                                const int orientationId = 0x0112;
 
-                                if (image.PropertyIdList.Contains(orientationId))
+                result.Remove(previousMessage);
-                                {
-                                    var item = image.GetPropertyItem(orientationId);
 
-                                    orient = BitConverter.ToInt16(item.Value, 0);
+                return result;
-                                
-                                    bitmap.SetPropertyItem(item);
-                                }
-
-                                var flipType = Utils.OrientationToFlipType(orient.ToString());
-
-                                bitmap.RotateFlip(flipType); 
-
-                                bitmap.Save(stream, ImageFormat.Jpeg);
-
-
-                                var bitmapImage = new BitmapImage();
-
-                                bitmapImage.BeginInit();
-                                bitmapImage.StreamSource = new MemoryStream(stream.ToArray());
-                                bitmapImage.EndInit();
-                                bitmapImage.Freeze();
-
-                                var chatMessage = new ChatMessage(groupId, 0, ChatDaten.LoggedInUser.Response.User.UserName, Path.GetFileName(pathToScaledFile), sendTime, true, memoryStream.Length, null, pathToScaledFile, Path.GetFileName(pathToScaledFile), null, bitmapImage, ChatMessageType.Image, ChatDaten.LoggedInUser.Response.User.Oid);
-
-                                result.Add(chatMessage);
-                            }
-                        }
-                    }
-                }
-                else
-                {
-                    var linkToThumbnail = $"{ChatDaten.ServerUrl}/document.png";
-
-                    var chatMessage = new ChatMessage(groupId, 0, ChatDaten.LoggedInUser.Response.User.UserName, Path.GetFileName(pathToScaledFile), sendTime, true, 0, pathToScaledFile, null, null, linkToThumbnail, null, ChatMessageType.Document, ChatDaten.LoggedInUser.Response.User.Oid);
-                    result.Add(chatMessage);
-                }
-
-                return AddSeparators(result);
             }
-            catch (Exception exception)
+            catch(Exception exception)
             {
-                ExceptionCallback?.Invoke(exception);
+                if(!(exception is IOException))
+                {
+                    ExceptionCallback?.Invoke(exception);
+                }
             }
 
             return result;
         }
 
+        private static BitmapImage GetImageFile(string pathToScaledFile, out long fileSize)
+        {
+            if(!File.Exists(pathToScaledFile) || !Constants.ImageFileExtensions.Contains(Path.GetExtension(pathToScaledFile).ToUpperInvariant()))
+            {
+                fileSize = 0L;
+                return null;
+            }
+
+            byte[] file;
+            using(Stream reader = File.Open(pathToScaledFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
+            {
+                file = Utils.ReadFully(reader);
+            }
+
+            using(var memoryStream = new MemoryStream(file))
+            {
+                var image = Image.FromStream(memoryStream);
+
+                using(var bitmap = new Bitmap(image))
+                {
+                    using(var stream = new MemoryStream())
+                    {
+                        short orient = 0;
+                        const int orientationId = 0x0112;
+
+                        if (image.PropertyIdList.Contains(orientationId))
+                        {
+                            var item = image.GetPropertyItem(orientationId);
+
+                            orient = BitConverter.ToInt16(item.Value, 0);
+
+                            bitmap.SetPropertyItem(item);
+                        }
+
+                        var flipType = Utils.OrientationToFlipType(orient.ToString());
+
+                        bitmap.RotateFlip(flipType);
+
+                        bitmap.Save(stream, ImageFormat.Jpeg);
+
+                        var bitmapImage = new BitmapImage();
+
+                        bitmapImage.BeginInit();
+                        bitmapImage.StreamSource = new MemoryStream(stream.ToArray());
+                        bitmapImage.EndInit();
+                        bitmapImage.Freeze();
+
+                        fileSize = memoryStream.Length;
+                        return bitmapImage;
+                    }
+                }
+            }
+        }
+
         public List<ChatMessage> AddFileToMessage(byte[] file, string fileName, long groupId, ChatMessage previousMessage)
         {
             var result = new List<ChatMessage>();
@@ -594,7 +526,7 @@ namespace ChatController.HauptKlassen
                 return result;
             }
 
-            if(previousMessage != null)
+            if(!(previousMessage is null))
             {
                 result.Add(previousMessage);
             }
@@ -637,13 +569,12 @@ namespace ChatController.HauptKlassen
             {
                 await SendFile(scaledImagePath, currentContact, originalFilePath, message);
             }
-            catch (Exception exception)
+            catch(Exception exception)
             {
                 ExceptionCallback?.Invoke(exception);
             }
         }
 
-        // WebRequest                                                                                                                                                                            
         private async Task SendFile(string pFile, Contact currentContact, string pOriginalFilePath, string message)
         {
             if(string.IsNullOrEmpty(pOriginalFilePath))
@@ -652,29 +583,24 @@ namespace ChatController.HauptKlassen
             }
 
             byte[] mediaFile;
-            using (Stream reader = File.OpenRead(pFile))
+            using(Stream reader = File.OpenRead(pFile))
             {
                 mediaFile = Utils.ReadFully(reader);
             }
-            
+
             var fileName = Path.GetFileName(pOriginalFilePath).ToLower();
 
-            if (Constants.ImageFileExtensions.Contains(Path.GetExtension(fileName).ToUpperInvariant()))
+            if(Constants.ImageFileExtensions.Contains(Path.GetExtension(fileName).ToUpperInvariant()))
             { 
                 fileName = fileName.Replace(".bmp", ".jpg");
-
-                await SendMediaMessage(fileName, currentContact.GroupId, mediaFile, message);
-            }
-            else
-            {
-                await SendMediaMessage(fileName, currentContact.GroupId, mediaFile, message);
             }
+                
+            await SendMediaMessage(fileName, currentContact.GroupId, mediaFile, message, pFile);
         }
         
         private HttpRequestMessage _HttpRequest;
 
-        // WebRequest
+        private async Task SendMediaMessage(string fileName, long groupId, byte[] mediaFile, string message, string pathToTempFile)
-        private async Task SendMediaMessage(string fileName, long groupId, byte[] mediaFile, string message)
         {
             try
             {
@@ -701,14 +627,11 @@ namespace ChatController.HauptKlassen
                     _HttpRequest.Headers.Add(Constants.CustomerId, ChatDaten.Kundennummer);
 
                     var httpClient = new HttpClient();
-                    var httpResponse = await httpClient.SendAsync(_HttpRequest, CancellationToken.None);//.ConfigureAwait(false);
+                    await httpClient.SendAsync(_HttpRequest, HttpCompletionOption.ResponseContentRead);
-
-                    var antwortResponse = await httpResponse.Content.ReadAsStringAsync();
                 }
             }
-            catch (Exception exception)
+            catch(Exception)
             {
-                ExceptionCallback?.Invoke(exception);
             }
         }
 
@@ -738,7 +661,7 @@ namespace ChatController.HauptKlassen
 
         public void SaveFileAs(ChatMessage pChatMessage)
         {
-            if (pChatMessage.PictureSource != null)
+            if (!(pChatMessage.PictureSource is null))
             {
                 SaveAs(1, Path.GetFileName(pChatMessage.OriginalImage), DownloadMediaFile(pChatMessage.OriginalImage));
             }
@@ -812,22 +735,24 @@ namespace ChatController.HauptKlassen
         {         
             var dataObject = Clipboard.GetDataObject();
 
-            if(dataObject == null)
+            if(dataObject is null)
             {
                 return;
             }
             
-            if (dataObject.GetDataPresent(DataFormats.FileDrop))
+            if(dataObject.GetDataPresent(DataFormats.FileDrop))
             {
                 try
                 {
-                    if (dataObject.GetData(DataFormats.FileDrop) is string[] fileList)
+                    if(dataObject.GetData(DataFormats.FileDrop) is string[] fileList)
                     {
-                        if (File.Exists(fileList[0]))
+                        var pathToFile = fileList[0];
+
+                        if(File.Exists(pathToFile))
                         {
-                            var fileName = Path.GetFileName(fileList[0]);
+                            var fileName = Path.GetFileName(pathToFile);
                             
-                            var mediaFile = File.ReadAllBytes(fileList[0]);
+                            var mediaFile = File.ReadAllBytes(pathToFile);
 
                             pChatMainControl.AddMessages(AddFileToMessage(mediaFile, fileName, pGroupOid, pChatMainControl.GetFirstMessage()));
                             
@@ -836,18 +761,18 @@ namespace ChatController.HauptKlassen
                             pChatMainControl.ChatListBox.Items.MoveCurrentToLast();
                             pChatMainControl.ChatListBox.ScrollIntoView(pChatMainControl.ChatListBox.Items.CurrentItem);
 
-                            await SendMediaMessage(fileName, pGroupOid, mediaFile, null);
+                            await SendMediaMessage(fileName, pGroupOid, mediaFile, null, pathToFile);
                         }
                     }
                 }
-                catch (Exception exception)
+                catch(Exception exception)
                 {
                     ExceptionCallback?.Invoke(exception);
                 }
             }
             else
             {
-                if (dataObject.GetDataPresent(DataFormats.Text))
+                if(dataObject.GetDataPresent(DataFormats.Text))
                 {
                     var text = (string) dataObject.GetData(DataFormats.StringFormat);
 
@@ -860,7 +785,7 @@ namespace ChatController.HauptKlassen
 
                     await SendMessage(text, pGroupOid);
                 }
-                else if (dataObject.GetDataPresent(DataFormats.Bitmap))
+                else if(dataObject.GetDataPresent(DataFormats.Bitmap))
                 {
                     var bitmap = (Bitmap) dataObject.GetData(DataFormats.Bitmap);
 
@@ -875,7 +800,7 @@ namespace ChatController.HauptKlassen
                     pChatMainControl.ChatListBox.Items.MoveCurrentToLast();
                     pChatMainControl.ChatListBox.ScrollIntoView(pChatMainControl.ChatListBox.Items.CurrentItem);
 
-                    await SendMediaMessage(imageName, pGroupOid, Utils.ImageToByteArray(image), null);
+                    await SendMediaMessage(imageName, pGroupOid, Utils.ImageToByteArray(image), null, null);
                 }
                 else
                 {
@@ -970,7 +895,6 @@ namespace ChatController.HauptKlassen
                 grid.Children.Clear();
                 grid.Children.Add(image);
 
-
                 window.SizeToContent = SizeToContent.WidthAndHeight;
                 window.Content = grid;
                 window.Margin = new Thickness(0);
@@ -978,7 +902,7 @@ namespace ChatController.HauptKlassen
 
                 window.ShowDialog();
             }
-            catch (Exception exception)
+            catch(Exception exception)
             {
                 ExceptionCallback?.Invoke(exception);
             }
@@ -1001,7 +925,7 @@ namespace ChatController.HauptKlassen
                     downloadCompletedCallback?.Invoke(imageSource, last ?? "Bild");
                 });
             }
-            catch (Exception exception)
+            catch(Exception exception)
             {
                 ExceptionCallback?.Invoke(exception);
             }
@@ -1033,14 +957,14 @@ namespace ChatController.HauptKlassen
             {
                 _Contacts.Clear();
                 
-                if(chatDaten?.Response != null)
+                if(!(chatDaten?.Response is null))
                 {
                     _Contacts.AddRange(GenerateContactsFromServerResponse(chatDaten.Response.Groups.ToArray()));
                 }
 
                 return _Contacts;
             }
-            catch (Exception exception)
+            catch(Exception exception)
             {
                 ExceptionCallback?.Invoke(exception);
                 return null;
@@ -1057,7 +981,7 @@ namespace ChatController.HauptKlassen
 
                 var latestMessage = groupInput.LastMessage;
 
-                if(latestMessage?.Text != null)
+                if(!(latestMessage?.Text is null))
                 {
                     var timeStamp = DateTime.Parse(latestMessage.Timestamp.Date);
                     var clientZone = TimeZoneInfo.Local;
@@ -1095,7 +1019,7 @@ namespace ChatController.HauptKlassen
 
                 if(pShouldUpdateLastTimeStamp)
                 {
-                    if(latestMessage?.Timestamp?.Date != null)
+                    if(!(latestMessage?.Timestamp?.Date is null))
                     {
                         var unixTimeStamp = DateTime.Parse(latestMessage.Timestamp.Date).GetUnixTimeStamp();
 
@@ -1114,15 +1038,15 @@ namespace ChatController.HauptKlassen
         {
             var result = new List<ChatMessage>();
 
-            foreach (var message in pMessages)
+            foreach(var message in pMessages)
             {
                 var time                   = DateTime.Parse(message.Timestamp.Date);
                 var clientZone             = TimeZoneInfo.Local;
                 var formattedTime          = TimeZoneInfo.ConvertTimeFromUtc(time, clientZone);
-                var isLoggedInUsersMessage = ChatDaten.Userid != null && message.UserId == ChatDaten.Userid.Value;
+                var isLoggedInUsersMessage = !(ChatDaten.Userid is null) && message.UserId == ChatDaten.Userid.Value;
-                var messageText            = message.Text ?? (string.IsNullOrEmpty(message.File) ? string.Empty : message.Original_Filename);
+                var messageText      = message.Text ?? (string.IsNullOrEmpty(message.File) ? string.Empty : message.Original_Filename);
 
-                if (!string.IsNullOrEmpty(message.File))
+                if(!string.IsNullOrEmpty(message.File))
                 {
                     var message2Add = Constants.ImageFileExtensions.Contains(Path.GetExtension(message.File).ToUpperInvariant()) ? //SmallerImage ist null
                         new ChatMessage(message.GroupId, message.Id, message.User_Name, messageText, formattedTime, isLoggedInUsersMessage, message.FileSize, message.Smaller_Image, message.File, message.Original_Filename, null, null, ChatMessageType.Image, message.UserId) :
@@ -1150,7 +1074,7 @@ namespace ChatController.HauptKlassen
             var previousMessage = messagesWithoutSeparators.OrderBy(message => message.SendTime).FirstOrDefault();
             foreach(var message in messagesWithoutSeparators.OrderBy(message => message.SendTime))
             {
-                if(!message.Equals(previousMessage) && previousMessage != null)
+                if(!message.Equals(previousMessage) && !(previousMessage is null))
                 {
                     if(message.SendTime.Date != previousMessage.SendTime.Date)
                     {
@@ -1210,10 +1134,6 @@ namespace ChatController.HauptKlassen
             }
         }
 
-        public void SendBroadcastMessage()
-        {
-            throw new NotImplementedException("SendBroadcastMessage implementieren!");
-        }
 
 
 

ChatController/HauptKlassen/Login.cs

@@ -337,14 +337,14 @@ namespace ChatController.HauptKlassen
                     }
                     else
                     {
-                        if (userDaten.Error?.ChatCodeFailed != null)
+                        if(!(userDaten.Error?.ChatCodeFailed is null))
                         {
                             if (_ShouldShowMessageBox)
                             {
                                 MessageBox.Show("Fehler: " + userDaten.Error.ChatCodeFailed[0] + "\nBitte überprüfen Sie die Anmeldeinformationen.", "Info", MessageBoxButton.OK, MessageBoxImage.Error);
                             }
                         }
-                        else if (userDaten.Error?.LoginFailed != null)
+                        else if(!(userDaten.Error?.LoginFailed is null))
                         {
                             if (_ShouldShowMessageBox)
                             {
@@ -360,9 +360,9 @@ namespace ChatController.HauptKlassen
                     MessageBox.Show(response.Content, "Fehler", MessageBoxButton.OK, MessageBoxImage.Error);
                 }
             }
-            catch (Exception e)
+            catch(Exception e)
             {
-                if (_ShouldShowMessageBox)
+                if(_ShouldShowMessageBox)
                 {
                     MessageBox.Show("Fehler:" + e.Message, "Fehler", MessageBoxButton.OK, MessageBoxImage.Error);
                 }
@@ -387,8 +387,6 @@ namespace ChatController.HauptKlassen
                     
                     if (!string.IsNullOrEmpty(serverResponse))
                     {
-                        Debug.WriteLine($"'ChatGruppenDaten' (Gruppen): {serverResponse}");
-
                         var jsonDaten = JsonConvert.DeserializeObject<ChatGruppenDaten>(serverResponse);
 
                         _AllGroups = jsonDaten;
@@ -422,7 +420,7 @@ namespace ChatController.HauptKlassen
             {
                 var connectionData = JsonConvert.DeserializeObject<UserDaten>(response.Content);
 
-                if(connectionData != null && connectionData.Success)
+                if(connectionData?.Success ?? false)
                 {
                     _AuthToken = connectionData.Response.User.Token;
                     _UserId = connectionData.Response.User.Oid;
@@ -440,16 +438,16 @@ namespace ChatController.HauptKlassen
                 {
                     var errorMessage = string.Empty;
 
-                    if (connectionData?.Error?.ChatCodeFailed != null)
+                    if(!(connectionData?.Error?.ChatCodeFailed is null))
                     {
                         errorMessage = $"Fehler: {connectionData.Error.ChatCodeFailed[0]}";
                     }
-                    else if (connectionData?.Error?.LoginFailed != null)
+                    else if(!(connectionData?.Error?.LoginFailed is null))
                     {
                         errorMessage = $"Fehler: {connectionData.Error.LoginFailed[0]}";
                     }
 
-                    if (!string.IsNullOrWhiteSpace(errorMessage))
+                    if(!string.IsNullOrWhiteSpace(errorMessage))
                     {
                         exceptionCallback?.Invoke(errorMessage);
                     }

ChatController/LoginControl.xaml.cs

@@ -6,7 +6,7 @@ using System.Reflection;
 using System.Runtime.CompilerServices;
 using System.Text;
 using System.Windows;
-using System.Windows.Controls;
+using System.Windows.Forms;
 using System.Windows.Threading;
 using ChatController.Annotations;
 using ChatController.HauptKlassen;
@@ -15,6 +15,7 @@ using ChatController.Utilities;
 using ChatController.Utilities.Extensions;
 using Cursors = System.Windows.Input.Cursors;
 using MessageBox = System.Windows.MessageBox;
+using Panel = System.Windows.Controls.Panel;
 using Path = System.IO.Path;
 
 namespace ChatController
@@ -104,7 +105,7 @@ namespace ChatController
 
         private void StartWaitingImmediately()
         {
-            if (_WaitLayer == null)
+            if (_WaitLayer is null)
             {
                 _WaitLayer = new ChatControlWaitLayer();
                 Panel.SetZIndex(_WaitLayer, int.MaxValue);
@@ -117,7 +118,7 @@ namespace ChatController
         {
             Dispatcher.BeginInvoke(DispatcherPriority.Normal, (Action) delegate
             {
-                if (_WaitLayer != null)
+                if(!(_WaitLayer is null))
                 {
                     RootGrid.Children.Remove(_WaitLayer);
                     _WaitLayer = null;
@@ -183,7 +184,7 @@ namespace ChatController
                     {
                         string line;
 
-                        while((line = streamReader.ReadLine()) != null)
+                        while(!((line = streamReader.ReadLine()) is null))
                         {
                             var encodedTextBytes = Convert.FromBase64String(line);
 
@@ -199,6 +200,56 @@ namespace ChatController
                         _ChatCode = lines[1];
                     }
                 }
+
+                #if DEBUG
+                var debugFile = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "debug-info.txt");
+                if (File.Exists(debugFile))
+                {
+                    using(var streamReader2 = new StreamReader(debugFile, true))
+                    {
+                        string line;
+
+                        var counter = 0;
+
+                        while(!((line = streamReader2.ReadLine()) is null))
+                        {
+                            if(counter == 0)
+                            {
+                                try
+                                {
+                                    var encodedTextBytes = Convert.FromBase64String(line);
+
+                                    var plainText = Encoding.UTF8.GetString(encodedTextBytes);
+
+                                    UserName = plainText;
+                                }
+                                catch (Exception)
+                                {
+                                    MessageBox.Show("Der Zeile muss im Base64-Format kodiert sein.", "Fehler", MessageBoxButton.OK, MessageBoxImage.Error);
+                                }
+                                
+                            }
+                            else if(counter == 1)
+                            {
+                                try
+                                {
+                                    var encodedTextBytes = Convert.FromBase64String(line);
+
+                                    var plainText = Encoding.UTF8.GetString(encodedTextBytes);
+
+                                    Password = plainText;
+                                }
+                                catch (Exception)
+                                {
+                                    MessageBox.Show("Der Zeile muss im Base64-Format kodiert sein.", "Fehler", MessageBoxButton.OK, MessageBoxImage.Error);
+                                }
+                            }
+
+                            counter++;
+                        }
+                    }
+                }
+                #endif
             }
             catch(Exception e)
             {
@@ -249,14 +300,14 @@ namespace ChatController
                 var localAppData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
                 var companyFilePath = Path.Combine(localAppData, "beyondSoft");
 
-                if (!Directory.Exists(companyFilePath))
+                if(!Directory.Exists(companyFilePath))
                 {
                     Directory.CreateDirectory(companyFilePath);
                 }
 
                 var bewoFilePath = Path.Combine(companyFilePath, "OwnChat");
 
-                if (!Directory.Exists(bewoFilePath))
+                if(!Directory.Exists(bewoFilePath))
                 {
                     Directory.CreateDirectory(bewoFilePath);
                 }

ChatController/OwnChatMessageBox.xaml

@@ -0,0 +1,50 @@
+<Window x:Class="ChatController.OwnChatMessageBox"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:converter="clr-namespace:ChatController.Converter"
+             mc:Ignorable="d" ResizeMode="NoResize" Title="{Binding Path=Title, UpdateSourceTrigger=PropertyChanged}"
+             d:DesignHeight="450" d:DesignWidth="400" WindowStartupLocation="CenterOwner"
+             Height="150" Width="400" >
+    <Window.Resources>
+        <converter:OwnChatNullVisibilityConverter x:Key="NullVisibilityConverter" />
+
+        <Style x:Key="OrangeButtonStyle" TargetType="{x:Type Button}">
+            <Setter Property="BorderBrush" Value="#FF5A00" />
+            <Setter Property="Background" Value="#FF5A00" />
+            <Setter Property="Foreground" Value="White"></Setter>
+            <Setter Property="Template">
+                <Setter.Value>
+                    <ControlTemplate TargetType="{x:Type Button}">
+                        <Border x:Name="Border" Background="#FF5A00" CornerRadius="5" Padding="5,2">
+                            <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
+                        </Border>
+                        <ControlTemplate.Triggers>
+                            <Trigger Property="IsMouseOver" Value="True">
+                                <Setter Property="Background" Value="#FF988F" TargetName="Border" />
+                            </Trigger>
+                            <Trigger Property="IsPressed" Value="True">
+                                <Setter Property="Background" Value="#FF7654" TargetName="Border" />
+                            </Trigger>
+                            <Trigger Property="IsEnabled" Value="False">
+                                <Setter Property="Background" Value="LightGray" TargetName="Border" />
+                            </Trigger>
+                        </ControlTemplate.Triggers>
+                    </ControlTemplate>
+                </Setter.Value>
+            </Setter>
+        </Style>
+    </Window.Resources>
+    <Grid Margin="5" HorizontalAlignment="Center">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="*" />
+            <RowDefinition Height="Auto" />
+        </Grid.RowDefinitions>
+        <TextBlock Grid.Row="0" Text="{Binding Path=MessageBoxText, UpdateSourceTrigger=PropertyChanged}" FontSize="14" Margin="5" TextWrapping="Wrap"/>
+        <StackPanel Grid.Row="1" Orientation="Horizontal" HorizontalAlignment="Stretch">
+            <Button Margin="5" FontSize="14" Content="{Binding Path=PositiveButtonText, UpdateSourceTrigger=PropertyChanged}" Width="150" Style="{StaticResource OrangeButtonStyle}" Height="30" Click="PositiveButton_OnClick" Visibility="{Binding Path=PositiveButtonText, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource NullVisibilityConverter}}" />
+            <Button Margin="5" FontSize="14" Content="{Binding Path=CloseButtonText, UpdateSourceTrigger=PropertyChanged}" Width="150" Style="{StaticResource OrangeButtonStyle}" Click="CloseButton_OnClick" />
+        </StackPanel>
+    </Grid>
+</Window>

ChatController/OwnChatMessageBox.xaml.cs

@@ -0,0 +1,76 @@
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+using System.Windows;
+using ChatController.Annotations;
+
+namespace ChatController
+{
+    public partial class OwnChatMessageBox : INotifyPropertyChanged
+    {
+        private string _MessageBoxText;
+
+        public string MessageBoxText
+        {
+            get => _MessageBoxText;
+            set
+            {
+                _MessageBoxText = value;
+                OnPropertyChanged(nameof(MessageBoxText));
+            }
+        }
+
+        private string _PositiveButtonText;
+        public string PositiveButtonText
+        {
+            get => _PositiveButtonText;
+            set
+            {
+                _PositiveButtonText = value;
+                OnPropertyChanged(nameof(PositiveButtonText));
+            }
+        }
+
+        private string _CloseButtonText;
+        public string CloseButtonText
+        {
+            get => _CloseButtonText;
+            set
+            {
+                _CloseButtonText = value;
+                OnPropertyChanged(nameof(CloseButtonText));
+            }
+        }
+
+        public OwnChatMessageBox(string positiveButtonText, string closeButtonText, string messageBoxText, string title)
+        {
+            InitializeComponent();
+
+            DataContext = this;
+
+            PositiveButtonText = positiveButtonText;
+            CloseButtonText = string.IsNullOrWhiteSpace(closeButtonText) ? "Schließen" : closeButtonText;
+            MessageBoxText = messageBoxText;
+            Title = title;
+        }
+
+        public event PropertyChangedEventHandler PropertyChanged;
+
+        [NotifyPropertyChangedInvocator]
+        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
+        {
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+        }
+
+        private void PositiveButton_OnClick(object sender, RoutedEventArgs e)
+        {
+            DialogResult = true;
+            Close();
+        }
+
+        private void CloseButton_OnClick(object sender, RoutedEventArgs e)
+        {
+            DialogResult = false;
+            Close();
+        }
+    }
+}

ChatController/Properties/Annotations1.cs

@@ -137,7 +137,7 @@ namespace ChatController.Annotations
   /// </summary>
   /// <example><code>
   /// void Foo(string param) {
-  ///   if (param == null)
+  ///   if (param is null)
   ///     throw new ArgumentNullException("par"); // Warning: Cannot resolve symbol
   /// }
   /// </code></example>

ChatController/Utilities/ChatMessageFileWrapper.cs

@@ -5,11 +5,14 @@ using System.Runtime.CompilerServices;
 using System.Windows.Media;
 using System.Windows.Media.Imaging;
 using ChatController.Annotations;
+using ChatController.Core;
 
 namespace ChatController.Utilities
 {
-    public class BroadcastMessage : INotifyPropertyChanged
+    public class ChatMessageFileWrapper : INotifyPropertyChanged
     {
+        public string FileName => !string.IsNullOrWhiteSpace(OriginalFilePath) ? Path.GetFileName(OriginalFilePath) : null;
+
         private string _OriginalFilePath;
         public string OriginalFilePath
         {
@@ -18,6 +21,7 @@ namespace ChatController.Utilities
             {
                 _OriginalFilePath = value;
                 OnPropertyChanged(nameof(OriginalFilePath));
+                OnPropertyChanged(nameof(FileName));
             }
         }
 
@@ -32,29 +36,39 @@ namespace ChatController.Utilities
             }
         }
 
-        private ImageSource _BroadcastMessageImageSource;
+        private ImageSource _ChatMessageImageSource;
 
-        public ImageSource BroadcastMessageImageSource
+        public ImageSource ChatMessageImageSource
         {
-            get => _BroadcastMessageImageSource;
+            get => _ChatMessageImageSource;
-            set
+            private set
             {
-                _BroadcastMessageImageSource = value;
+                _ChatMessageImageSource = value;
-                OnPropertyChanged(nameof(BroadcastMessageImageSource));
+                OnPropertyChanged(nameof(ChatMessageImageSource));
             }
         }
 
-        public BroadcastMessage(string originalFilePath, string scaledFilePath)
+        public ChatMessageFileWrapper(string originalFilePath, string scaledFilePath, string thumbnailUrl)
         {
             OriginalFilePath = originalFilePath;
             ScaledFilePath = scaledFilePath;
 
-            var bitmap = new BitmapImage();
+            var uri = new Uri(scaledFilePath);
-            bitmap.BeginInit();
-            bitmap.UriSource = new Uri(scaledFilePath);
-            bitmap.EndInit();
 
-            BroadcastMessageImageSource = bitmap;
+            if (Constants.ImageFileExtensions.Contains(Path.GetExtension(scaledFilePath).ToUpperInvariant()) && uri.IsFile)
+            {
+                var bitmap = new BitmapImage(uri);
+                bitmap.Freeze();
+
+                ChatMessageImageSource = bitmap;
+            }
+            else
+            {
+                Utils.DownloadDocumentThumbnail(thumbnailUrl, imageSource =>
+                {
+                    ChatMessageImageSource = imageSource;
+                });
+            }
         }
 
         public event PropertyChangedEventHandler PropertyChanged;

ChatController/Utilities/Extensions/ObservableSortCollection.cs

@@ -49,7 +49,7 @@ namespace ChatController.Utilities.Extensions
 
         public void Sort()
         {
-            if (_Comparer != null)
+            if (!(_Comparer is null))
             {
                 DisconnectHandler();
                 var lTemp = this.ToList();

ChatController/Utilities/FileUtils.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using System.Drawing;
 using System.Drawing.Drawing2D;
 using System.Drawing.Imaging;
@@ -13,6 +14,13 @@ namespace ChatController.Utilities
         {
             try
             {
+                var isImageFile = Constants.ImageFileExtensions.Contains(Path.GetExtension(pFile).ToUpperInvariant());
+
+                if(!isImageFile)
+                {
+                    return pFile;
+                }
+
                 byte[] mediaFile;
                 using(Stream reader = File.OpenRead(pFile))
                 {
@@ -79,7 +87,8 @@ namespace ChatController.Utilities
                     graphics.DrawImage(scaledBitmap, (int)width, (int)height);
                 }
 
-                var filePath = Path.GetTempPath() + Guid.NewGuid() + pFormat;
+                // tmp_img_owch_
+                var filePath = $"{Path.GetTempPath()}{Guid.NewGuid()}_tmp_img_owch{pFormat}";
 
                 if(pFormat.Equals(".JPG") || pFormat.Equals(".JPE") || pFormat.Equals(".JPEG") || pFormat.Equals(".BMP"))
                 {
@@ -120,12 +129,37 @@ namespace ChatController.Utilities
                 return pFile;
             }
         }
-
+        
         public static bool CheckFileSize(string pathToFile, long maxFileSize)
         {
             var fileInfo = new FileInfo(pathToFile);
-
+            
             return fileInfo.Length > maxFileSize;
         }
+
+        public static bool IsFileLocked(string path)
+        {
+            if(!File.Exists(path))
+            {
+                return false;
+            }
+
+            try
+            {
+                var file = new FileInfo(path);
+
+                using (var stream = file.Open(FileMode.Open, FileAccess.Read, FileShare.None))
+                {
+                    stream.Close();
+                }
+            }
+            catch(IOException ioException)
+            {
+                Debug.WriteLine($"Error (FileUtils.IsFileLocked): {ioException.Message}");
+                return true;
+            }
+
+            return false;
+        }
     }
 }

ChatController/Utilities/Utils.cs

@@ -14,14 +14,11 @@ using System.Windows;
 using System.Windows.Documents;
 using System.Windows.Interop;
 using System.Windows.Media;
-using System.Windows.Media.Animation;
 using System.Windows.Media.Imaging;
 using ChatController.Core;
 using RestSharp;
 using MessageBox = System.Windows.MessageBox;
 using PixelFormat = System.Drawing.Imaging.PixelFormat;
-using Point = System.Drawing.Point;
-using Size = System.Drawing.Size;
 
 namespace ChatController.Utilities
 {
@@ -138,7 +135,7 @@ namespace ChatController.Utilities
 
             var cachedImage = cache.GetImageSourceFromCache(key, uri, cacheCategory);
 
-            if (cachedImage != null)
+            if(!(cachedImage is null))
             {
                 callback?.Invoke(cachedImage);
                 return;
@@ -151,15 +148,38 @@ namespace ChatController.Utilities
             });
         }
 
+        public static void DownloadDocumentThumbnail(string uri, Action<ImageSource> callback)
+        {
+            if (string.IsNullOrEmpty(uri))
+            {
+                callback?.Invoke(null);
+                return;
+            }
+
+            var cache = OwnChatCache.GetInstance();
+
+            if(!(cache.DocumentThumbnail is null))
+            {
+                callback?.Invoke(cache.DocumentThumbnail);
+                return;
+            }
+
+            DownloadImage(uri, imageSource =>
+            {
+                cache.DocumentThumbnail = imageSource;
+                callback?.Invoke(imageSource);
+            });
+        }
+
         private static ImageSource GetDefaultImageSource(bool pIsGroup, bool pIsEmployee)
         {
             var defaultImage = Constants.EmployeeDefaultImagePath;
 
-            if (pIsGroup)
+            if(pIsGroup)
             {
                 defaultImage = pIsEmployee ? Constants.TeamDefaultImagePath : Constants.NormalGroupDefaultImagePath;
             }
-            else if (!pIsEmployee)
+            else if(!pIsEmployee)
             {
                 defaultImage = Constants.CustomerDefaultImagePath;
             }
@@ -176,21 +196,28 @@ namespace ChatController.Utilities
 
         public static ImageSource GetPicturePlaceholder()
         {
-            var resultBitmapImage = new BitmapImage();
+            var cache = OwnChatCache.GetInstance();
 
-            resultBitmapImage.BeginInit();
+            if(cache.ImagePlaceholder is null)
-            resultBitmapImage.UriSource = new Uri(Constants.ImagePlaceholderPath);
+            {
-            resultBitmapImage.EndInit();
+                var resultBitmapImage = new BitmapImage();
-            resultBitmapImage.Freeze();
 
-            return resultBitmapImage;
+                resultBitmapImage.BeginInit();
+                resultBitmapImage.UriSource = new Uri(Constants.ImagePlaceholderPath);
+                resultBitmapImage.EndInit();
+                resultBitmapImage.Freeze();
+
+                cache.ImagePlaceholder = resultBitmapImage;
+            }
+
+            return cache.ImagePlaceholder;
         }
 
         public static string ReadStream(WebResponse response)
         {
             var dataStream = response.GetResponseStream();
 
-            if (dataStream == null)
+            if(dataStream is null)
             {
                 return null;
             }
@@ -214,21 +241,21 @@ namespace ChatController.Utilities
                 var localAppData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
                 var companyFilePath = Path.Combine(localAppData, Resource.CompanyName);
 
-                if (!Directory.Exists(companyFilePath))
+                if(!Directory.Exists(companyFilePath))
                 {
                     Directory.CreateDirectory(companyFilePath);
                 }
 
                 var bewoFilePath = Path.Combine(companyFilePath, Resource.ApplicationFolderName);
 
-                if (!Directory.Exists(bewoFilePath))
+                if(!Directory.Exists(bewoFilePath))
                 {
                     Directory.CreateDirectory(bewoFilePath);
                 }
 
                 return bewoFilePath;
             }
-            catch (Exception exception)
+            catch(Exception exception)
             {
                 MessageBox.Show("Fehler beim Anlegen des Anwendungsordners. Sie besitzen nicht die erforderlichen Rechte, bitte wenden Sie sich an Ihren Systemadministrator.\n" + exception.Message, "BeWoPlaner", MessageBoxButton.OK, MessageBoxImage.Exclamation);
             }
@@ -251,15 +278,15 @@ namespace ChatController.Utilities
         {
             try
             {
-                using (var memoryStream = new MemoryStream())
+                using(var memoryStream = new MemoryStream())
                 {
                     pImage.Save(memoryStream, ImageFormat.Bmp);
                     return memoryStream.ToArray();
                 }
             }
-            catch (Exception e)
+            catch(Exception exception)
             {
-                MessageBox.Show("Fehler: " + e.Message, "Fehler", MessageBoxButton.OK);
+                MessageBox.Show("Fehler: " + exception.Message, "Fehler", MessageBoxButton.OK);
                 return null;
             }
         }
@@ -337,7 +364,7 @@ namespace ChatController.Utilities
 
         public static byte[] ReadFully(Stream pStream)
         {
-            using (var memStream = new MemoryStream())
+            using(var memStream = new MemoryStream())
             {
                 pStream.CopyTo(memStream);
                 return memStream.ToArray();
@@ -346,7 +373,7 @@ namespace ChatController.Utilities
 
         public static RotateFlipType OrientationToFlipType(string orientation)
         {
-            switch (int.Parse(orientation))
+            switch(int.Parse(orientation))
             {
                 case 1:
                     return RotateFlipType.RotateNoneFlipNone;
@@ -453,7 +480,7 @@ namespace ChatController.Utilities
                 https://test.ownchat.de/message/view-image/{customerid}/{group}/{height}/{filename}
              */
 
-            if (uri != null && uri.Contains("/"))
+            if(uri?.Contains("/") ?? false)
             {
                 var splitUri = uri.Split('/');
 
@@ -477,7 +504,7 @@ namespace ChatController.Utilities
         {
             var result = new ObservableCollection<Inline>();
 
-            if(messageText == null)
+            if(messageText is null)
             {
                 return result;
             }

PrototypChat/App.xaml.cs

@@ -1,17 +1,6 @@
-using System;
+namespace ownChat
-using System.Collections.Generic;
-using System.Configuration;
-using System.Data;
-using System.Linq;
-using System.Threading.Tasks;
-using System.Windows;
-
-namespace ownChat
 {
-    /// <summary>
+    public partial class App
-    /// Interaktionslogik für "App.xaml"
-    /// </summary>
-    public partial class App : Application
     {
     }
 }

PrototypChat/MainWindow.xaml

@@ -5,8 +5,8 @@
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:cc="clr-namespace:ChatController;assembly=ChatController"
         mc:Ignorable="d" WindowStartupLocation="CenterScreen"  Icon="pack://application:,,,/ChatController;component/Ressourcen/ownchat_icon.png"
-        SizeChanged="MainWindow_OnSizeChanged" MinHeight="610"
+        MinHeight="610"
-        Title="ownChat Desktop" Height="700" Width="900" x:Name="MainView" Closed="MainWindow_OnClosed">
+        Title="ownChat Desktop" Height="700" Width="900" Closed="MainWindow_OnClosed">
     <Grid>
         <cc:ChatMainControl x:Name="ChatMainControl" OnEmojii="ChatMainControl_OnOnEmojii"></cc:ChatMainControl>
     </Grid>

PrototypChat/MainWindow.xaml.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Diagnostics;
 using System.Threading;
 using System.Windows;
 
@@ -21,7 +20,6 @@ namespace ownChat
             ChatMainControl.ContainingWindow = this;
 
             ChatMainControl.InitMitChatdaten(x);
-            ChatMainControl.ResetStyle();
 
             _EmojiView = new ChatEmojisView(ChatMainControl);
         }
@@ -50,10 +48,5 @@ namespace ownChat
 
             Environment.Exit(0);
         }
-
-        private void MainWindow_OnSizeChanged(object sender, SizeChangedEventArgs e)
-        {
-            Debug.WriteLine($"+++>ActualHeight: {ActualHeight}");
-        }
     }
 }

PrototypChat/Properties/Annotations.cs

@@ -137,7 +137,7 @@ namespace ownChat.Annotations
   /// </summary>
   /// <example><code>
   /// void Foo(string param) {
-  ///   if (param == null)
+  ///   if (param is null)
   ///     throw new ArgumentNullException("par"); // Warning: Cannot resolve symbol
   /// }
   /// </code></example>