Massennachricht hinzugefügt

Optik an die vom Android- und Webclient angepasst
Asynchrone Methoden verbessert

ChatController/ChatController.csproj

@@ -67,6 +67,7 @@
       <DependentUpon>ChatMainControl.xaml</DependentUpon>
     </Compile>
     <Compile Include="Converter\BoolToVisibilityConverter.cs" />
+    <Compile Include="Converter\BroadcastCheckBoxVisibilityMultiConverter.cs" />
     <Compile Include="Converter\StringEmptyToVisibilityConverter.cs" />
     <Compile Include="Converter\StringToBoolConverter.cs" />
     <Compile Include="Converter\UserProfilePictureVisibilityConverter.cs" />
@@ -99,10 +100,14 @@
       <DesignTime>True</DesignTime>
       <DependentUpon>Resource.resx</DependentUpon>
     </Compile>
+    <Compile Include="Utilities\BroadcastMessage.cs" />
+    <Compile Include="Utilities\BroadcastProgressReportModel.cs" />
     <Compile Include="Utilities\Constants.cs" />
     <Compile Include="Utilities\Extensions\ControlExtensions.cs" />
     <Compile Include="Utilities\Extensions\DateTimeExtensions.cs" />
+    <Compile Include="Utilities\Extensions\ObservableSortCollection.cs" />
     <Compile Include="Utilities\FileUtils.cs" />
+    <Compile Include="Utilities\ListItemHelper.cs" />
     <Compile Include="Utilities\OwnChatEnums.cs" />
     <Compile Include="Utilities\SyncFileInfoStruct.cs" />
     <Compile Include="Utilities\Utils.cs" />
@@ -148,6 +153,7 @@
   </ItemGroup>
   <ItemGroup>
     <Content Include="ownchat_favicon.ico" />
+    <Resource Include="Ressourcen\TasksSolid.png" />
     <Resource Include="Ressourcen\ownchat_image_placeholder.png" />
     <Resource Include="Ressourcen\warning-exclamation-mark.png" />
     <None Include="packages.config" />

ChatController/ChatKlassen/ChatMessage.cs

@@ -4,10 +4,11 @@ using System.ComponentModel;
 using System.Windows.Documents;
 using System.Windows.Media;
 using ChatController.Core;
-using ChatController.HauptKlassen;
 using ChatController.Utilities;
 using static System.Windows.HorizontalAlignment;
 using Application = System.Windows.Application;
+using Brush = System.Windows.Media.Brush;
+using Color = System.Windows.Media.Color;
 using HorizontalAlignment = System.Windows.HorizontalAlignment;
 
 namespace ChatController.ChatKlassen
@@ -147,9 +148,11 @@ namespace ChatController.ChatKlassen
 
         public string SendTimeString => SendTime.Date == DateTime.Today ? $"Heute {SendTime:HH:mm}" : SendTime.ToString("dd. MMM HH:mm");
 
-        public Brush BorderBrush => IsSeparator ? new SolidColorBrush(Colors.Transparent) : IsMyMessage ? new SolidColorBrush(Color.FromRgb(255, 90, 0)) : new SolidColorBrush(Color.FromRgb(229, 229, 229));
+        public Brush BorderBrush => IsSeparator ? new SolidColorBrush(Colors.Transparent) : IsMyMessage ? new SolidColorBrush(Color.FromRgb(255, 90, 0)) : new SolidColorBrush(Color.FromRgb(255, 255, 255));
 
-        public Brush HighlightedBorderBrush => IsSeparator ? new SolidColorBrush(Colors.Transparent) : IsMyMessage ? new SolidColorBrush(Color.FromRgb(255, 153, 153)) : new SolidColorBrush(Color.FromRgb(247, 247, 247));
+        public Brush HighlightedBorderBrush => IsSeparator ? new SolidColorBrush(Colors.Transparent) : IsMyMessage ? new SolidColorBrush(Color.FromRgb(255, 152, 143)) : new SolidColorBrush(Color.FromRgb(247, 247, 247));
+
+        public Brush TextColor => !IsMyMessage && !IsSeparator ? new SolidColorBrush(Colors.Black) : new SolidColorBrush(Colors.White);
 
         public Brush Foreground => new BrushConverter().ConvertFromString("#505050") as SolidColorBrush;
 

ChatController/ChatKlassen/Contact.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
+using System.Windows;
 using System.Windows.Media;
 using ChatController.Core;
 using ChatController.LoginKlassen;
@@ -179,4 +180,14 @@ namespace ChatController.ChatKlassen
             handler?.Invoke(this, new PropertyChangedEventArgs(propertyName));
         }      
     }
+
+    public class ContactDependencyObject : DependencyObject
+    {
+        public Contact Contact { get; set; }
+
+        public ContactDependencyObject(Contact contact)
+        {
+            Contact = contact;
+        }
+    }
 }

ChatController/ChatMainControl.xaml

@@ -7,18 +7,132 @@
              xmlns:chatKlassen="clr-namespace:ChatController.ChatKlassen"
              xmlns:core="clr-namespace:ChatController.Core"
              xmlns:chatController="clr-namespace:ChatController"
-             mc:Ignorable="d" x:Name="ChatControlling"
+             xmlns:utilities="clr-namespace:ChatController.Utilities"
+             mc:Ignorable="d"
              d:DesignHeight="300" d:DesignWidth="600" 
              Loaded="ChatMainControl_OnLoaded"
              SnapsToDevicePixels="True" d:DataContext="{d:DesignData ChatMainControl}">
     <UserControl.Resources>
         <converter:BoolToVisibilityConverter x:Key="BoolToVisibilityConverter" />
         <converter:StringEmptyToVisibilityConverter x:Key="StringEmptyToVisibilityConverter" />
-        <converter:StringToBoolConverter x:Key="StringToBoolConverter" />
         <converter:UserProfilePictureVisibilityConverter x:Key="UserProfilePictureVisibilityConverter" />
+        <converter:BroadcastCheckBoxVisibilityMultiConverter x:Key="BroadcastCheckBoxVisibilityMultiConverter" />
+        
 
-        <SolidColorBrush x:Key="DarkBackColor" Color="#FFA9B8C2" />
+        <!--<SolidColorBrush x:Key="DarkBackColor" Color="#A9B8C2" />-->
-        <SolidColorBrush x:Key="LightBackColor" Color="#E8EFF4" />
+        <SolidColorBrush x:Key="DarkBackColor" Color="#A9B8C2" />
+        <SolidColorBrush x:Key="LightBackColor" Color="#F3F3F3" />
+
+        <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>
+
+        <Style x:Key="CloseButtonStyle" TargetType="{x:Type Button}">
+            <Setter Property="MinWidth" Value="0" />
+            <Setter Property="MinHeight" Value="0" />
+            <Setter Property="Width" Value="Auto" />
+            <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.Resources>
+                            <Storyboard x:Key="Timeline1">
+                                <DoubleAnimationUsingKeyFrames BeginTime="00:00:00" Storyboard.TargetName="glow" Storyboard.TargetProperty="(UIElement.Opacity)">
+                                    <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>
+                                    <BeginStoryboard Storyboard="{StaticResource Timeline1}" />
+                                </Trigger.EnterActions>
+                                <Trigger.ExitActions>
+                                    <BeginStoryboard x:Name="Timeline2_BeginStoryboard" Storyboard="{StaticResource Timeline2}" />
+                                </Trigger.ExitActions>
+                            </Trigger>
+                        </ControlTemplate.Triggers>
+                    </ControlTemplate>
+                </Setter.Value>
+            </Setter>
+        </Style>
 
         <Style x:Key="MainNavigationScrollViewer" TargetType="{x:Type ScrollViewer}">
             <Setter Property="OverridesDefaultStyle" Value="True"/>
@@ -77,30 +191,47 @@
                 <Setter.Value>
                     <ControlTemplate>
                         <Grid>
-                            <Border x:Name="ItemBorder" MinHeight="20" Background="White" BorderThickness="0,0,0,1" BorderBrush="{StaticResource LightBackColor}">
+                            <Border x:Name="ItemBorder" MinHeight="20" Background="White" BorderThickness="0,0,0,0" BorderBrush="{StaticResource LightBackColor}">
                             </Border>
-                            <Border x:Name="ItemContent"  MinHeight="20">
+                            <Border x:Name="ItemContent" MinHeight="20">
                                 <Grid HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Margin="5,3,5,3" OpacityMask="{x:Null}" SnapsToDevicePixels="True">
                                     <Grid.ColumnDefinitions>
-                                        <ColumnDefinition Width="7"/>
+                                        <ColumnDefinition Width="Auto"/>
                                         <ColumnDefinition Width="35"/>
                                         <ColumnDefinition Width="7"/>
                                         <ColumnDefinition Width="Auto"/>
                                         <ColumnDefinition Width="7"/>
                                         <ColumnDefinition Width="*"/>
                                     </Grid.ColumnDefinitions>
+                                    <CheckBox Grid.Column="0" VerticalAlignment="Center" Margin="0,0,7,0" 
+                                              Click="ContactCheckBox_OnClick" Checked="ContactCheckBox_OnChecked" Unchecked="ContactCheckBox_OnChecked"
+                                              IsChecked="{Binding Path=(utilities:ListItemHelper.IsChecked), Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">
+                                        <CheckBox.Visibility>
+                                            <MultiBinding Converter="{StaticResource BroadcastCheckBoxVisibilityMultiConverter}">
+                                                <Binding Path="Chat.IsInBroadcastMode" RelativeSource="{RelativeSource FindAncestor, AncestorType={x:Type chatController:ChatMainControl}}" UpdateSourceTrigger="PropertyChanged" />
+                                                <Binding Path="Contact.IsChatMessageInputGridVisible" />
+                                            </MultiBinding>
+                                        </CheckBox.Visibility>
+                                        <CheckBox.Style>
+                                            <Style TargetType="{x:Type CheckBox}">
+                                                <Style.Triggers>
+                                                    <DataTrigger Binding="{Binding Path=(utilities:ListItemHelper.IsChecked), Mode=TwoWay}" Value="False" />
+                                                </Style.Triggers>
+                                            </Style>
+                                        </CheckBox.Style>
+                                    </CheckBox>
                                     <Ellipse Grid.Column="1" Width='32' Height='32' RenderOptions.BitmapScalingMode="HighQuality">
                                         <Ellipse.Fill>
-                                            <ImageBrush ImageSource='{Binding Image, UpdateSourceTrigger=PropertyChanged}' Stretch='UniformToFill' RenderOptions.BitmapScalingMode="HighQuality" />
+                                            <ImageBrush ImageSource='{Binding Contact.Image, UpdateSourceTrigger=PropertyChanged}' Stretch='UniformToFill' RenderOptions.BitmapScalingMode="HighQuality" />
                                         </Ellipse.Fill>
                                     </Ellipse>
-                                    <Grid Grid.Column="3"  >
+                                    <Grid Grid.Column="3">
                                         <Grid.RowDefinitions>
                                             <RowDefinition Height="*" />
                                             <RowDefinition Height="*"/>
                                         </Grid.RowDefinitions>
-                                        <TextBlock Text="{Binding Path=Name, FallbackValue=FirstName}" Foreground="{Binding Path=AccentColorBrush}" FontSize="16" Margin="1" />
+                                        <TextBlock Text="{Binding Path=Contact.Name, FallbackValue=FirstName}" Foreground="{Binding Path=Contact.AccentColorBrush}" FontSize="16" Margin="1" />
-                                        <TextBlock Text="{Binding Path=ReceivedMessage.Text}" Grid.Row="1" FontSize="14"  Foreground="{Binding Path=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>
@@ -171,8 +302,8 @@
 
                 <Grid Grid.Column="0" Grid.Row="0" >
                     <Grid.RowDefinitions>
-                        <RowDefinition  Height="50"/>
+                        <RowDefinition Height="50"/>
-                        <RowDefinition  Height="*"/>
+                        <RowDefinition Height="*"/>
                     </Grid.RowDefinitions>
                     <Grid.ColumnDefinitions>
                         <ColumnDefinition Width="*"/>
@@ -188,9 +319,16 @@
                             <ColumnDefinition Width="Auto"/>
                         </Grid.ColumnDefinitions>
 
-                        <StackPanel x:Name="ReloadGruppen" Grid.Row="0" Grid.Column="1" Height="25" Width="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" VerticalAlignment="Center" VerticalContentAlignment="Center"  Width="25" Height="25" Click="ButtonReloadGruppen_OnClick" >
+                            <Button Background="Transparent" HorizontalAlignment="Right"  BorderThickness="0" 
-                                <Image ToolTip="Gruppen Aktualisieren" Margin="0,0,0,0" Width="20" Height="20" Source="pack://application:,,,/ChatController;component/Ressourcen/SymbolRefresh32.png" RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
+                                    VerticalAlignment="Center" VerticalContentAlignment="Center" Width="25" Height="25" Click="ButtonReloadGruppen_OnClick" >
+                                <Image ToolTip="Gruppen Aktualisieren" Margin="0,0,0,0" Width="20" Height="20" 
+                                       Source="pack://application:,,,/ChatController;component/Ressourcen/SymbolRefresh32.png" RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
+                            </Button>
+                            <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>
                         </StackPanel>
 
@@ -201,12 +339,16 @@
                     <!-- region Kontaktliste -->
                     <Grid Grid.Column="0" Grid.Row="1"  >
                         <Grid.RowDefinitions>
-                            <RowDefinition  Height="*"/>
+                            <RowDefinition Height="Auto"/>
+                            <RowDefinition Height="*"/>
                         </Grid.RowDefinitions>
                         <Grid.ColumnDefinitions>
                             <ColumnDefinition Width="*"/>
                         </Grid.ColumnDefinitions>
-                        <ListView x:Name="Clientlist" HorizontalAlignment="Stretch" Grid.Row="0" Grid.Column="0"   VerticalAlignment="Stretch" BorderThickness="0" Background="White"
+                        <CheckBox Grid.Row="0" Margin="5" x:Name="SelectAllContactsCheckBox" FontSize="16" Content="Alle auswählen" VerticalContentAlignment="Center" VerticalAlignment="Center" Height="35" 
+                                  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>
@@ -254,6 +396,7 @@
                              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}}"
                              d:DataContext="{d:DesignData ChatMessage}">
                         <ListBox.ItemContainerStyle>
                             <Style TargetType="ListBoxItem">
@@ -334,11 +477,15 @@
 
                                             <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" Source="{Binding Path=Thumbnail, UpdateSourceTrigger=PropertyChanged}" Stretch="Uniform" VerticalAlignment="Center" HorizontalAlignment="Center" />
+                                                    <Image ToolTip="Dokument öffnen" Height="{Binding ThumbnailPlaceholderHeight, UpdateSourceTrigger=PropertyChanged}" Width="150" 
-                                                    <Image MaxWidth="300" Height="{Binding PicturePlaceholderHeight, UpdateSourceTrigger=PropertyChanged}" Source="{Binding Path=PictureSource, UpdateSourceTrigger=PropertyChanged}" x:Name="imgChatMessage" Stretch="UniformToFill" />
+                                                           Source="{Binding Path=Thumbnail, UpdateSourceTrigger=PropertyChanged}" 
+                                                           Stretch="Uniform" VerticalAlignment="Center" HorizontalAlignment="Center" />
+                                                    <Image MaxHeight="300"
+                                                           Source="{Binding Path=PictureSource, UpdateSourceTrigger=PropertyChanged}" 
+                                                           x:Name="imgChatMessage" Stretch="Uniform" RenderOptions.BitmapScalingMode="HighQuality" />
                                                     <core:OwnChatRichTextBox VerticalAlignment="Center" InlineList="{Binding MessageInlines, UpdateSourceTrigger=PropertyChanged}" 
                                                                              MinWidth="0" MaxWidth="{Binding MessageMaxWidth}" FontSize="14" IsReadOnly="True"
-                                                                             HorizontalAlignment="{Binding HorizontalAlignmentValue}"
+                                                                             HorizontalAlignment="{Binding HorizontalAlignmentValue}" Foreground="{Binding TextColor, UpdateSourceTrigger=PropertyChanged, Mode=OneWay}"
                                                                              BorderThickness="0" Background="Transparent" IsDocumentEnabled="True" Margin="-5,0,0,0" />
                                                 </StackPanel>
                                                 <StackPanel DockPanel.Dock="Left" Margin="0,0,0,0">
@@ -368,6 +515,24 @@
                         </ListBox.ItemTemplate>
                     </ListBox>
 
+                    <Grid Grid.Row="1" Grid.Column="0" Visibility="{Binding Path=Chat.IsInBroadcastMode, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}">
+                        <Grid.RowDefinitions>
+                            <RowDefinition Height="Auto" />
+                            <RowDefinition Height="*" />
+                        </Grid.RowDefinitions>
+                        <Button Grid.Row="0" Grid.Column="0" Margin="5" Height="20" Width="20" HorizontalAlignment="Right" Style="{DynamicResource CloseButtonStyle}" Click="AbortBroadcastButton_OnClick" />
+                        <StackPanel Grid.Row="1" Orientation="Vertical" Margin="5" VerticalAlignment="Center">
+                            <TextBlock Text="{Binding BroadcastInfoText, UpdateSourceTrigger=PropertyChanged}" Foreground="Black"
+                                       HorizontalAlignment="Center" TextWrapping="Wrap" TextAlignment="Center" FontSize="16" Margin="20, 0" />
+                            <ProgressBar Margin="20, 5" Value="{Binding BroadcastProgressValue, UpdateSourceTrigger=PropertyChanged}" Height="20" />
+                            <Image MaxHeight="300" RenderOptions.BitmapScalingMode="HighQuality" 
+                                   Source="{Binding Path=BroadcastMessage.BroadcastMessageImageSource, UpdateSourceTrigger=PropertyChanged}" Stretch="Uniform"
+                                   />
+                            <Button Content="Abbrechen" Width="75" Style="{StaticResource OrangeButtonStyle}" Height="25" Margin="0, 5"
+                                    Click="CancelBroadcastButton_OnClick" />
+                        </StackPanel>
+                    </Grid>
+
                     <Grid Grid.Row="2" Visibility="{Binding ChatMessageInputGridVisibility}" VerticalAlignment="Stretch" MinHeight="25" MaxHeight="200">
                         <Grid.ColumnDefinitions>
                             <ColumnDefinition Width="*" />
@@ -392,6 +557,7 @@
                                  GotFocus="Chatbox_OnGotFocus" 
                                  AcceptsReturn="True"
                                  KeyDown="Chatbox_OnKeyDownHandler"
+                                 KeyUp="Chatbox_OnKeyUpHandler"
                                  TextChanged="Chatbox_OnTextChanged">
                             <TextBox.Resources>
                                 <Style TargetType="{x:Type Border}">
@@ -417,62 +583,29 @@
                                 </Style>
                             </TextBlock.Resources>
                         </TextBlock>
-                        <Button Grid.Column="1"
+                        <Button Grid.Column="1" Margin="2" x:Name="MediaButton" Background="Transparent" 
-                                Margin="2" 
+                                Width="28" Height="28" BorderThickness="0" Padding="2"
-                                x:Name="MediaButton" 
+                                Visibility="{Binding Chat.IsInBroadcastMode, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource BoolToVisibilityConverter}}"
-                                Background="Transparent" 
+                                VerticalAlignment="Bottom" ToolTip="Datei einfügen" Click="MediaButton_OnClick" >
-                                Width="28" 
-                                Height="28"
-                                BorderThickness="0" 
-                                Padding="2"
-                                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"/>
                         </Button>
-                        <Button Grid.Column="2" 
+                        <Button Grid.Column="1" Margin="2" Background="Transparent"
-                                Width="28"
+                                Width="28" Height="28" BorderThickness="0" Padding="2"
-                                Height="28"
+                                Visibility="{Binding Path=Chat.IsInBroadcastMode, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}"
-                                BorderThickness="0" 
+                                VerticalAlignment="Bottom" ToolTip="Datei einfügen" Click="AddMediaFileToBroadcastMessage_OnClick">
-                                Background="Transparent" 
+                            <Image Width="22" Height="22" Source="pack://application:,,,/ChatController;component/Ressourcen/paperclip2.png" RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
-                                x:Name="EmojiButton" 
+                        </Button>
-                                Margin="2" 
+                        <Button Grid.Column="2" Width="28" Height="28" BorderThickness="0" 
-                                Padding="0" 
+                                Background="Transparent" x:Name="EmojiButton" Margin="2" Padding="0" 
-                                VerticalAlignment="Bottom" 
+                                VerticalAlignment="Bottom" ToolTip="Emoji einfügen" Click="EmojiButton_OnClick">
-                                ToolTip="Emoji einfügen" 
-                                Click="EmojiButton_OnClick">
                             <Image Width="24" Height="24" Source='pack://application:,,,/ChatController;component/Ressourcen/glucklicher.png'  RenderOptions.BitmapScalingMode="HighQuality" HorizontalAlignment="Center" />
                         </Button>
-                        <Button x:Name="SendButton" Height="25" Content="Senden" Margin="3" Grid.Column="3" VerticalAlignment="Bottom" 
+                        <Button x:Name="SendButton" Height="25" Content="Senden" Margin="3" Grid.Column="3" VerticalAlignment="Bottom" Style="{StaticResource OrangeButtonStyle}"
-                                Click="SendButton_OnClick" IsEnabled="{Binding ElementName=Chatbox, Path=Text, Converter={StaticResource StringToBoolConverter}}">
+                                Visibility="{Binding Chat.IsInBroadcastMode, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource BoolToVisibilityConverter}}"
-                            <Button.Style>
+                                Click="SendButton_OnClick" IsEnabled="{Binding IsSendButtonEnabled, UpdateSourceTrigger=PropertyChanged}" />
-                                <Style TargetType="{x:Type Button}">
+                        <Button Height="25" Content="Senden" Margin="3" Grid.Column="3" VerticalAlignment="Bottom" Style="{StaticResource OrangeButtonStyle}"
-                                    <Setter Property="BorderBrush" Value="#ff5e00" />
+                                Visibility="{Binding Path=Chat.IsInBroadcastMode, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource BoolToVisibilityConverter}, ConverterParameter=reverse}"
-                                    <Setter Property="Background" Value="#ff5e00" />
+                                Click="SendBroatcastButton_OnClick" IsEnabled="{Binding IsBroadcastButtonEnabled, UpdateSourceTrigger=PropertyChanged}" />
-                                    <Setter Property="Foreground" Value="White"></Setter>
-                                    <Setter Property="Template">
-                                        <Setter.Value>
-                                            <ControlTemplate TargetType="{x:Type Button}">
-                                                <Border x:Name="Border" Background="#ff5300" CornerRadius="5" Padding="5,2">
-                                                    <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
-                                                </Border>
-                                                <ControlTemplate.Triggers>
-                                                    <Trigger Property="IsMouseOver" Value="True">
-                                                        <Setter Property="Background" Value="#ff9999" TargetName="Border" />
-                                                    </Trigger>
-                                                    <Trigger Property="IsPressed" Value="True">
-                                                        <Setter Property="Background" Value="#ff3a00" TargetName="Border" />
-                                                    </Trigger>
-                                                    <Trigger Property="IsEnabled" Value="False">
-                                                        <Setter Property="Background" Value="LightGray" TargetName="Border" />
-                                                    </Trigger>
-                                                </ControlTemplate.Triggers>
-                                            </ControlTemplate>
-                                        </Setter.Value>
-                                    </Setter>
-                                </Style>
-                            </Button.Style>
-                        </Button>
                     </Grid>
                 </Grid>
             </Grid>

ChatController/ChatMainControl.xaml.cs

@@ -8,6 +8,7 @@ using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Text;
 using System.Threading;
+using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Data;
@@ -25,6 +26,7 @@ using ChatController.Utilities;
 using ChatController.Utilities.Extensions;
 using Application  = System.Windows.Forms.Application;
 using Button       = System.Windows.Controls.Button;
+using CheckBox = System.Windows.Controls.CheckBox;
 using Cursors      = System.Windows.Input.Cursors;
 using DataFormats  = System.Windows.DataFormats;
 using KeyEventArgs = System.Windows.Input.KeyEventArgs;
@@ -112,11 +114,17 @@ namespace ChatController
             }
         }
 
-        public ObservableCollection<Contact> ContactList
+        // ToDo: Hier die ContactDepenencyObject-Klasse benutzen wie im Kalender des BeWoPlaners!
+        public ObservableSortCollection<ContactDependencyObject> ContactList
         {
-            get
+            get => _ContactList ?? (_ContactList = new ObservableSortCollection<ContactDependencyObject>());
+
+            set
             {
-                return _ContactList == null ? new ObservableCollection<Contact>() : new ObservableCollection<Contact>(_ContactList.OrderByDescending(contact => contact.TimeStamp));
+                _ContactList = new ObservableSortCollection<ContactDependencyObject>(value);
+                _ContactList.Sort((x, y) => DateTime.Compare(y.Contact.TimeStamp, x.Contact.TimeStamp));
+
+                OnPropertyChanged(nameof(ContactList));
             }
         }
 
@@ -124,16 +132,21 @@ namespace ChatController
         {
             get
             {
-                if(_CurrentContact is null)
+                if(_CurrentContact is null && Chat?.IsInBroadcastMode == false)
                 {
                     return Visibility.Collapsed;
                 }
 
-                return _CurrentContact.IsChatMessageInputGridVisible ? Visibility.Visible : Visibility.Collapsed;
+                if(false == (Chat?.IsInBroadcastMode ?? false) && !(_CurrentContact is null))
+                {
+                    return _CurrentContact.IsChatMessageInputGridVisible ? Visibility.Visible : Visibility.Collapsed;
+                }
+
+                return Chat?.IsInBroadcastMode ?? false ? Visibility.Visible : Visibility.Collapsed;
             }
         }
 
-        private List<Contact> _ContactList;
+        private ObservableSortCollection<ContactDependencyObject> _ContactList;
         
         private bool _ScrollPrueferAktivieren;
 
@@ -150,19 +163,18 @@ namespace ChatController
         public ChatMainControl()
         {
             InitializeComponent();
-            
+
             _ThreadExceptionImageSource = new BitmapImage(new Uri("pack://application:,,,/ChatController;component/Ressourcen/warning-exclamation-mark.png", UriKind.Absolute));
 
             _ChatMessages = new ObservableCollection<ChatMessage>();
             ChatMessages = CollectionViewSource.GetDefaultView(_ChatMessages) as ListCollectionView;
+
             if (!(ChatMessages is null))
             {
                 ChatMessages.CustomSort = new ChatMessageComparer();
             }
 
             DataContext = this;
-
-            ReloadGruppen.Visibility = Visibility.Collapsed;
         }
 
         private void ContainingWindowOnDeactivated(object sender, EventArgs e)
@@ -202,20 +214,27 @@ namespace ChatController
 
             OnPropertyChanged(nameof(Chat));
 
-            _ContactList = Chat.AddContacts();
+            _ContactList = new ObservableSortCollection<ContactDependencyObject>();
+
+            foreach(var contact in Chat.AddContacts())
+            {
+                ContactList.Add(new ContactDependencyObject(contact));
+            }
+
+            ContactList.Sort((x, y) => DateTime.Compare(y.Contact.TimeStamp, x.Contact.TimeStamp));
 
             OnPropertyChanged(nameof(ContactList));
 
             ReadNewSyncFile();
 
-            foreach (var contact in _ContactList)
+            foreach (var contactDependencyObject in _ContactList)
             {
-                if (_GroupId2DateTime.ContainsKey(contact.GroupId))
+                if (_GroupId2DateTime.ContainsKey(contactDependencyObject.Contact.GroupId))
                 {
-                    var isUnread = _GroupId2DateTime[contact.GroupId].IsUnread;
+                    var isUnread = _GroupId2DateTime[contactDependencyObject.Contact.GroupId].IsUnread;
 
-                    contact.IsNewMessage = isUnread;
+                    contactDependencyObject.Contact.IsNewMessage = isUnread;
-                    contact.HasUnreadMessages = contact.IsNewMessage;
+                    contactDependencyObject.Contact.HasUnreadMessages = contactDependencyObject.Contact.IsNewMessage;
                 }
             }
 
@@ -230,11 +249,11 @@ namespace ChatController
         {
             var notificationIcon = Resource.ownchat_favicon;
 
-            var contact = _ContactList.FirstOrDefault(a => a.GroupId == pGroupId);
+            var contact = _ContactList.FirstOrDefault(a => a.Contact.GroupId == pGroupId);
 
             if (contact != null)
             {
-                notificationIcon = Utils.ImageSourceToIcon(contact.Image);
+                notificationIcon = Utils.ImageSourceToIcon(contact.Contact.Image);
             }
 
             var notifyIcon = new NotifyIcon { Icon = notificationIcon, Visible = true, Tag = pMessage };
@@ -255,10 +274,10 @@ namespace ChatController
 
                 _ContainingWindow.Activate();
 
-                var selectedContact = _ContactList?.FirstOrDefault(f => f?.GroupId == pGroupId);
+                var selectedContact = _ContactList?.FirstOrDefault(f => f?.Contact.GroupId == pGroupId);
                 if(selectedContact != null)
                 {
-                    SelectContact(selectedContact);
+                    SelectContact(selectedContact.Contact);
                 }
             };
             
@@ -314,9 +333,14 @@ namespace ChatController
 
         private void Clientlist_OnSelectionChanged(object sender, SelectionChangedEventArgs e)
         {
-            if(Clientlist?.SelectedItem is Contact selectedContact)
+            if(Chat.IsInBroadcastMode)
             {
-                SelectContact(selectedContact);
+                return;
+            }
+
+            if(Clientlist?.SelectedItem is ContactDependencyObject selectedContactDependencyObject)
+            {
+                SelectContact(selectedContactDependencyObject.Contact);
             }
         }
 
@@ -324,7 +348,7 @@ namespace ChatController
         {
             try
             {
-                if (pContact == null)
+                if (pContact is null)
                 {
                     return;
                 }
@@ -346,7 +370,7 @@ namespace ChatController
                 var currentContact = pContact;
                 pContact.IsNewMessage = false;
 
-                var shouldChangeIcon = _ContactList.Any(contact => contact.IsNewMessage);
+                var shouldChangeIcon = _ContactList.Any(contact => contact.Contact.IsNewMessage);
                 if (shouldChangeIcon)
                 {
                     ContainingWindow.Icon = Utils.ConvertIconToImageSource(Resource.ownchat_favicon);
@@ -354,9 +378,12 @@ namespace ChatController
 
                 CurrentContact = currentContact;
 
-                if (Clientlist.Items.Contains(pContact))
+                foreach(ContactDependencyObject item in Clientlist.Items)
                 {
-                    Clientlist.SelectedItem = pContact;
+                    if(item.Contact.Equals(pContact))
+                    {
+                        Clientlist.SelectedItem = item;
+                    }
                 }
 
                 _ChatMessages.Clear();
@@ -460,9 +487,9 @@ namespace ChatController
             }
         }
 
-        private void PasteOnClick(object sender, RoutedEventArgs routedEventArgs)
+        private async void PasteOnClick(object sender, RoutedEventArgs routedEventArgs)
         {
-            Chat.Paste(CurrentContact.GroupId,this);          
+            await Chat.Paste(CurrentContact.GroupId,this);
         }
 
         private void CopyOnClick(object sender, RoutedEventArgs routedEventArgs)
@@ -582,7 +609,7 @@ namespace ChatController
             }
         }
 
-        private void MediaButton_OnClick(object sender, RoutedEventArgs e)
+        private async void MediaButton_OnClick(object sender, RoutedEventArgs e)
         {
             if(CurrentContact != null)
             {
@@ -600,7 +627,7 @@ namespace ChatController
                         return;
                     }
 
-                    if (!string.IsNullOrWhiteSpace(pathToScaledImage))
+                    if (File.Exists(pathToScaledImage))
                     {
                         _ChatMessages.AddRangeIfElementsNotIn(Chat.AddNewFile(pathToScaledImage, pathToOriginalImage, CurrentContact.GroupId, GetFirstMessage()));
 
@@ -610,7 +637,7 @@ namespace ChatController
 
                         ChatListBox.ScrollIntoView(currentChatMessage);
 
-                        Chat.SendFileToContact(CurrentContact, pathToScaledImage,pathToOriginalImage);
+                        await Chat.SendFileToContact(CurrentContact, pathToScaledImage, pathToOriginalImage, Chatbox.Text);
 
                         if (!string.IsNullOrWhiteSpace(pathToScaledImage) && !pathToScaledImage.Equals(pathToOriginalImage) && File.Exists(pathToScaledImage))
                         {
@@ -625,8 +652,14 @@ namespace ChatController
             }
         }
 
-        private void SendButton_OnClick(object sender, RoutedEventArgs e)
+        private async void SendButton_OnClick(object sender, RoutedEventArgs e)
         {
+            if(Chat.IsInBroadcastMode)
+            {
+                SendBroadcastMessage();
+                return;
+            }
+
             if(CurrentContact != null && !string.IsNullOrEmpty(Chatbox.Text))
             {
                 var messages2Add = Chat.AddNewMessage(Chatbox.Text, CurrentContact.GroupId, GetFirstMessage());
@@ -639,12 +672,10 @@ namespace ChatController
 
                 WpfUtils.ScrollToBottomOfListBox(ChatListBox);
 
-                Chat.SendMessage(Chatbox.Text, CurrentContact.GroupId);
+                await Chat.SendMessage(Chatbox.Text, CurrentContact.GroupId);
 
                 Chatbox.Text = string.Empty;
 
-                Thread.Sleep(500);
-
                 DoSynchro();
             }
         }
@@ -672,12 +703,15 @@ namespace ChatController
 
                 //        ChatListBox.Items.MoveCurrentToLast();
                 //        ChatListBox.ScrollIntoView(ChatListBox.Items.CurrentItem);
-                       
+
                 //        Chat.SendMessage(Chatbox.Text, CurrentContact.GroupId);
 
                 //        Chatbox.Text = string.Empty;
                 //    }
                 //}
+
+                OnPropertyChanged(nameof(IsBroadcastButtonEnabled));
+                OnPropertyChanged(nameof(IsSendButtonEnabled));
             }
             catch (Exception ed)
             {
@@ -685,6 +719,12 @@ namespace ChatController
             }
         }
 
+        private void Chatbox_OnKeyUpHandler(object sender, KeyEventArgs e)
+        {
+            OnPropertyChanged(nameof(IsBroadcastButtonEnabled));
+            OnPropertyChanged(nameof(IsSendButtonEnabled));
+        }
+
         public delegate void EmojiiDelegate(Button button);
 
         public event EmojiiDelegate OnEmojii;
@@ -725,20 +765,23 @@ namespace ChatController
                     ChatMessages.MoveCurrentToFirst();
 
                     var currentChatMessage = ChatMessages.CurrentItem;
-                    
-                    var selectedContact = (Contact) Clientlist.SelectedItem;
 
-                    Chat.LoadMoreMessagesAsync(selectedContact, GetFirstMessage(), chatMessages =>
+                    if(!(Clientlist.SelectedItem is null))
                     {
-                        this.Dispatch(() =>
+                        var selectedContact = ((ContactDependencyObject) Clientlist.SelectedItem).Contact;
+
+                        Chat.LoadMoreMessagesAsync(selectedContact, GetFirstMessage(), chatMessages =>
                         {
-                            EndWaiting();
+                            this.Dispatch(() =>
+                            {
+                                EndWaiting();
 
-                            _ChatMessages.AddRangeIfElementsNotIn(chatMessages);
+                                _ChatMessages.AddRangeIfElementsNotIn(chatMessages);
 
-                            ChatListBox.ScrollIntoView(currentChatMessage);
+                                ChatListBox.ScrollIntoView(currentChatMessage);
+                            });
                         });
-                    });
+                    }
                 }
             }         
         }
@@ -782,19 +825,25 @@ namespace ChatController
                             {
                                 foreach (var newContact in updatedContacts)
                                 {
-                                    if (contact.GroupId == newContact.GroupId)
+                                    if (contact.Contact.GroupId == newContact.GroupId)
                                     {
                                         // ReceivedMessage kann null sein!
-                                        if (contact.ReceivedMessage != null && !contact.ReceivedMessage.Id.Equals(newContact.ReceivedMessage?.Id))
+                                        if (contact.Contact.ReceivedMessage != null && !contact.Contact.ReceivedMessage.Id.Equals(newContact.ReceivedMessage?.Id))
                                         {
-                                            contact.ReceivedMessage = newContact.ReceivedMessage;
+                                            contact.Contact.ReceivedMessage = newContact.ReceivedMessage;
-                                            contact.TimeStamp = newContact.TimeStamp;
+                                            contact.Contact.TimeStamp = newContact.TimeStamp;
+
+                                            Contact selectedContact = null;
+
+                                            if(Clientlist.SelectedItem is ContactDependencyObject selectedContactDependencyObject)
+                                            {
+                                                selectedContact = selectedContactDependencyObject.Contact;
+                                            }
 
-                                            var selectedContact = (Contact)Clientlist.SelectedItem;
                                             // Angemeldeter Benutzer
                                             var userOid = Chat.ChatDaten.LoggedInUser.Response.User.Oid;
 
-                                            var senderId = contact.ReceivedMessage?.UserId;
+                                            var senderId = contact.Contact.ReceivedMessage?.UserId;
                                             var receiverId = userOid;
                                             var receiverGroupId = newContact.GroupId;
                                             var selectedGroupId = selectedContact?.GroupId;
@@ -812,18 +861,18 @@ namespace ChatController
                                             // Wenn der momentan ausgewählte Kontakt der aktuelle Kontakt in der Schleife ist, werden die Nachrichten nicht als ungelesen angezeigt, sonst schon.
                                             if (CurrentContact != null && newContact.GroupId == CurrentContact.GroupId)
                                             {
-                                                contact.HasUnreadMessages = false;
+                                                contact.Contact.HasUnreadMessages = false;
                                             }
                                             else
                                             {
-                                                contact.HasUnreadMessages = true;
+                                                contact.Contact.HasUnreadMessages = true;
-                                                contact.IsNewMessage = true;
+                                                contact.Contact.IsNewMessage = true;
                                             }
                                         }
                                     }
                                 }
 
-                                if (!updatedContacts.Contains(contact))
+                                if (!updatedContacts.Contains(contact.Contact))
                                 {
                                     _ContactList.ToList().Remove(contact);
                                 }
@@ -853,7 +902,7 @@ namespace ChatController
 
         private void ListenForMessagesForCurrentContact(Contact pCurrentContact)
         {
-            if (!ShouldInterruptContactsThread)
+            if (!ShouldInterruptContactsThread && !(CurrentContact is null))
             {
                 Chat.CheckIfNewMessagesExistAsync(CurrentContact.GroupId, hasNewMessages =>
                 {
@@ -888,7 +937,12 @@ namespace ChatController
                 return true;
             }
 
-            return (item as Contact).Name.IndexOf(Suche.Text, StringComparison.OrdinalIgnoreCase) >= 0;
+            if(item is ContactDependencyObject contactDependencyObject)
+            {
+                return contactDependencyObject.Contact.Name.IndexOf(Suche.Text, StringComparison.OrdinalIgnoreCase) >= 0;
+            }
+
+            return false;
         }
 
         private void Chat_OnMouseDoubleClick(object sender, MouseButtonEventArgs e)
@@ -1021,7 +1075,13 @@ namespace ChatController
                 {
                     this.Dispatch(() =>
                     {
-                        _ContactList = Chat.UpdateContacts(data); // <- dauert eine Sekunde!
+                        ContactList = new ObservableSortCollection<ContactDependencyObject>();
+                        foreach(var contact in Chat.UpdateContacts(data))// <- dauert eine Sekunde!
+                        {
+                            ContactList.Add(new ContactDependencyObject(contact));
+                        }
+                        ContactList.Sort((x, y) => DateTime.Compare(y.Contact.TimeStamp, x.Contact.TimeStamp));
+
                         OnPropertyChanged(nameof(ContactList));
 
                         ReadNewSyncFile();
@@ -1054,9 +1114,9 @@ namespace ChatController
                 {
                     Encoding enc = new UTF8Encoding();
 
-                    foreach (var contact in _ContactList.ToList().Where(contact => contact.ReceivedMessage != null))
+                    foreach (var contact in _ContactList.ToList().Where(contact => contact.Contact.ReceivedMessage != null))
                     {
-                        var text = contact.GroupId + ";" + contact.TimeStamp.ToUniversalTime() + ";" + contact.IsNewMessage + ";";
+                        var text = contact.Contact.GroupId + ";" + contact.Contact.TimeStamp.ToUniversalTime() + ";" + contact.Contact.IsNewMessage + ";";
                         var bytes = enc.GetBytes(text);
                         var base64String = Convert.ToBase64String(bytes);
 
@@ -1066,7 +1126,7 @@ namespace ChatController
                     File.SetAttributes(Path.Combine(Utils.GetAndCreateUserAppDataPath(), Resource.SyncFile2Name), FileAttributes.ReadOnly);
                 }
             }
-            catch (Exception exception)
+            catch (Exception)
             {
 
             }
@@ -1113,7 +1173,7 @@ namespace ChatController
                     Chat.LastTimeStamp = latestDateTime.GetUnixTimeStamp();
                 }
             }
-            catch (Exception e)
+            catch(Exception)
             {
                 
             }
@@ -1128,9 +1188,9 @@ namespace ChatController
 
             foreach(var contactItem in Clientlist.Items)
             {
-                if(contactItem is Contact contact && contact.HasUnreadMessages && !string.IsNullOrEmpty(contact.ReceivedMessage?.Text))
+                if(contactItem is ContactDependencyObject contactDependencyObject && contactDependencyObject.Contact.HasUnreadMessages && !string.IsNullOrEmpty(contactDependencyObject.Contact.ReceivedMessage?.Text))
                 {
-                    contacts.Add(contact);
+                    contacts.Add(contactDependencyObject.Contact);
                 }
             }
 
@@ -1146,9 +1206,9 @@ namespace ChatController
                 {
                     foreach(var groupId2DateTime in pGroupId2DateTime)
                     {
-                        if(contact.GroupId == groupId2DateTime.Key)
+                        if(contact.Contact.GroupId == groupId2DateTime.Key)
                         {
-                            contact.HasUnreadMessages = false;
+                            contact.Contact.HasUnreadMessages = false;
                         }
                     }
                 }
@@ -1195,9 +1255,9 @@ namespace ChatController
                         File.Delete(file);
                     }
                 }
-                catch (Exception e)
+                catch (Exception)
                 {
-                    //ignore
+                    //ignore okeee
                 }
             }
         }
@@ -1227,6 +1287,9 @@ namespace ChatController
             {
                 Chatbox.Height = 25;
             }
+
+            OnPropertyChanged(nameof(IsBroadcastButtonEnabled));
+            OnPropertyChanged(nameof(IsSendButtonEnabled));
         }
 
         public void AddMessages(List<ChatMessage> newMessages)
@@ -1238,5 +1301,272 @@ namespace ChatController
         {
             return _ChatMessages.FirstOrDefault();
         }
+
+
+        #region Broadcast
+
+        public bool IsSendButtonEnabled => !string.IsNullOrEmpty(Chatbox.Text);
+
+        public bool IsBroadcastButtonEnabled
+        {
+            get
+            {
+                var isInBroadcastMode = Chat.IsInBroadcastMode;
+                var hasSelectedContacts = GetSelectedContacts().Any();
+                var hasTextOrFile = !string.IsNullOrEmpty(Chatbox.Text) || !(BroadcastMessage?.BroadcastMessageImageSource is null);
+
+                return isInBroadcastMode && hasSelectedContacts && hasTextOrFile;
+            }
+        }
+
+        private Contact _PreviousContact;
+
+        private CancellationTokenSource _CancellationTokenSource;
+
+        private string _DefaultBroadcastInfoText = "Dies ist eine Nachricht, die als Broadcast an alle ausgewählten Kontakte geschickt wird.";
+
+        private string _BroadcastInfoText;
+        public string BroadcastInfoText
+        {
+            get => _BroadcastInfoText ?? (_BroadcastInfoText = _DefaultBroadcastInfoText);
+            set
+            {
+                _BroadcastInfoText = $"{_DefaultBroadcastInfoText}{Environment.NewLine}{value}";
+                OnPropertyChanged(BroadcastInfoText);
+            }
+        }
+
+        private double _BroadcastProgressValue;
+        public double BroadcastProgressValue
+        {
+            get => _BroadcastProgressValue;
+            set
+            {
+                _BroadcastProgressValue = value;
+                OnPropertyChanged(nameof(BroadcastProgressValue));
+            }
+        }
+
+        private BroadcastMessage _BroadcastMessage;
+        public BroadcastMessage BroadcastMessage
+        {
+            get => _BroadcastMessage;
+            set
+            {
+                _BroadcastMessage = value;
+
+                OnPropertyChanged(nameof(BroadcastMessage));
+                OnPropertyChanged(nameof(IsBroadcastButtonEnabled));
+            }
+        }
+
+
+        private void BroadcastButton_OnClick(object sender, RoutedEventArgs e)
+        {
+            Chat.IsInBroadcastMode = !Chat.IsInBroadcastMode;
+
+            BroadcastProgressValue = 0;
+
+            DeselectAllContacts();
+
+            if (Chat.IsInBroadcastMode)
+            {
+                _CancellationTokenSource = new CancellationTokenSource();
+                _PreviousContact = CurrentContact;
+                CurrentContact = null;
+            }
+            else
+            {
+                CloseBroadcastMode();
+            }
+
+            OnPropertyChanged(nameof(IsSendButtonEnabled));
+            OnPropertyChanged(nameof(ChatMessageInputGridVisibility));
+            OnPropertyChanged(nameof(BroadcastMessage));
+        }
+
+        private void AbortBroadcastButton_OnClick(object sender, RoutedEventArgs e)
+        {
+            CloseBroadcastMode();
+        }
+        
+        private async void SendBroadcastMessage()
+        {
+            var selectedContacts = GetSelectedContacts();
+
+            if (selectedContacts.Count == 0 || string.IsNullOrEmpty(Chatbox.Text) && BroadcastMessage.BroadcastMessageImageSource is null)
+            {
+                return;
+            }
+
+            var progress = new Progress<BroadcastProgressReportModel>();
+            progress.ProgressChanged += ReportProgress;
+
+            try
+            {
+                await SendBroadcast(progress, _CancellationTokenSource.Token);
+            }
+            catch(OperationCanceledException)
+            {
+                BroadcastInfoText = "Der Broadcast wurde abgebrochen.";
+            }
+
+            DoSynchro();
+
+            CloseBroadcastMode();
+        }
+
+        private async Task SendBroadcast(IProgress<BroadcastProgressReportModel> progress, CancellationToken cancellationToken)
+        {
+            var count = 0;
+            var report = new BroadcastProgressReportModel();
+
+            var selectedContacts = GetSelectedContacts();
+
+            foreach (var contact in selectedContacts.Where(selectedContact => selectedContact.IsChatMessageInputGridVisible))
+            {
+                if(BroadcastMessage is null)
+                {
+                    await Chat.SendMessage(Chatbox.Text, contact.GroupId);
+                }
+                else
+                {
+                    await Chat.SendFileToContact(contact, BroadcastMessage.ScaledFilePath, BroadcastMessage.OriginalFilePath, Chatbox.Text);
+                }
+                
+                cancellationToken.ThrowIfCancellationRequested();
+
+                count++;
+                report.PercentageComplete = count * 100 / selectedContacts.Count;
+
+                progress.Report(report);
+            }
+        }
+
+        private void ReportProgress(object sender, BroadcastProgressReportModel e)
+        {
+            BroadcastProgressValue = e.PercentageComplete;
+        }
+
+        private void SelectAllContacts_OnClick(object sender, RoutedEventArgs e)
+        {
+            if(sender is CheckBox checkBox)
+            {
+                var isChecked = checkBox.IsChecked ?? false;
+
+                foreach (var contactDependencyObject in ContactList)
+                {
+                    contactDependencyObject.SetValue(ListItemHelper.IsCheckedProperty, isChecked);
+                }
+
+                OnPropertyChanged(nameof(ContactList));
+                OnPropertyChanged(nameof(IsBroadcastButtonEnabled));
+            }
+        }
+
+        private void SendBroatcastButton_OnClick(object sender, RoutedEventArgs e)
+        {
+            SendBroadcastMessage();
+        }
+
+        private void CancelBroadcastButton_OnClick(object sender, RoutedEventArgs e)
+        {
+            _CancellationTokenSource?.Cancel();
+            BroadcastMessage = null;
+            Chatbox.Text = string.Empty;
+        }
+
+        private void AddMediaFileToBroadcastMessage_OnClick(object sender, RoutedEventArgs e)
+        {
+            if(Chat.IsInBroadcastMode)
+            {
+                var originalFilePath = Chat.OpenFile();
+
+                if(File.Exists(originalFilePath))
+                {
+                    var scaledImagePath = FileUtils.ScaleImage(originalFilePath, Path.GetExtension(originalFilePath.ToUpperInvariant()), Chat.ChatDaten.MaxUploadSize);
+
+                    var isFileSizeTooLarge = FileUtils.CheckFileSize(scaledImagePath, Chat.ChatDaten.MaxUploadSize);
+
+                    if(isFileSizeTooLarge)
+                    {
+                        MessageBox.Show($"Die ausgewählte Datei ist zu groß. Die maximale Größe beträgt {Chat.ChatDaten.MaxUploadSize / 1000 / 1000} MB", "Senden nicht möglich", MessageBoxButton.OK, MessageBoxImage.Warning);
+                        return;
+                    }
+
+                    if(File.Exists(scaledImagePath))
+                    {
+                        if (BroadcastMessage is null)
+                        {
+                            BroadcastMessage = new BroadcastMessage(originalFilePath, scaledImagePath);
+                        }
+                    }
+                }
+            }
+        }
+
+        private void CloseBroadcastMode()
+        {
+            Chatbox.Text = string.Empty;
+
+            if(!(_PreviousContact is null))
+            {
+                SelectContact(_PreviousContact);
+            }
+
+            _CancellationTokenSource = null;
+            BroadcastMessage = null;
+            BroadcastProgressValue = 0;
+
+            DeselectAllContacts();
+
+            OnPropertyChanged(nameof(IsSendButtonEnabled));
+            OnPropertyChanged(nameof(ChatMessageInputGridVisibility));
+            OnPropertyChanged(nameof(BroadcastMessage));
+
+            Chat.IsInBroadcastMode = false;
+        }
+        #endregion
+
+        private void ContactCheckBox_OnClick(object sender, RoutedEventArgs e)
+        {
+            OnPropertyChanged(nameof(IsBroadcastButtonEnabled));
+        }
+
+        private void ContactCheckBox_OnChecked(object sender, RoutedEventArgs e)
+        {
+            UpdateContactSelection();
+        }
+
+        private void UpdateContactSelection()
+        {
+            OnPropertyChanged(nameof(ContactList));
+            OnPropertyChanged(nameof(IsBroadcastButtonEnabled));
+
+            SelectAllContactsCheckBox.IsChecked = GetSelectedContacts().Count == ContactList.Where(contactDependencyObject => contactDependencyObject.Contact.IsChatMessageInputGridVisible).ToList().Count;
+        }
+
+        private List<Contact> GetSelectedContacts()
+        {
+            var result = new List<Contact>();
+
+            foreach(var contactDependencyObject in ContactList.Where(contactDependencyObject => contactDependencyObject.Contact.IsChatMessageInputGridVisible))
+            {
+                if(contactDependencyObject.GetValue(ListItemHelper.IsCheckedProperty) is bool isChecked && isChecked)
+                {
+                    result.AddIfNotIn(contactDependencyObject.Contact);
+                }
+            }
+
+            return result;
+        }
+
+        private void DeselectAllContacts()
+        {
+            foreach (var contactDependencyObject in ContactList)
+            {
+                contactDependencyObject.SetValue(ListItemHelper.IsCheckedProperty, false);
+            }
+        }
     }
 }

ChatController/Converter/BroadcastCheckBoxVisibilityMultiConverter.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Globalization;
+using System.Windows;
+using System.Windows.Data;
+
+namespace ChatController.Converter
+{
+    public class BroadcastCheckBoxVisibilityMultiConverter : IMultiValueConverter
+    {
+        public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
+        {
+            if(values.Length == 2 && values[0] is bool isInBroadcastMode && values[1] is bool isChatMessageInputGridVisible)
+            {
+                if(isInBroadcastMode)
+                {
+                    return isChatMessageInputGridVisible ? Visibility.Visible : Visibility.Hidden;
+                }
+
+                return Visibility.Collapsed;
+            }
+
+            return Visibility.Collapsed;
+        }
+
+        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

ChatController/HauptKlassen/Chat.cs

@@ -3,6 +3,7 @@ using Newtonsoft.Json;
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.Drawing;
 using System.Drawing.Imaging;
 using System.IO;
@@ -10,8 +11,10 @@ using System.Linq;
 using System.Net;
 using System.Net.Http;
 using System.Net.Security;
+using System.Runtime.CompilerServices;
 using System.Security.Cryptography.X509Certificates;
 using System.Threading;
+using System.Threading.Tasks;
 using System.Web;
 using System.Windows;
 using System.Windows.Controls;
@@ -19,6 +22,7 @@ using System.Windows.Data;
 using System.Windows.Forms;
 using System.Windows.Media;
 using System.Windows.Media.Imaging;
+using ChatController.Annotations;
 using ChatController.Core;
 using ChatController.Extensions;
 using ChatController.LoginKlassen;
@@ -35,7 +39,7 @@ using MessageBox = System.Windows.MessageBox;
 namespace ChatController.HauptKlassen
 {
     // Ist quasi das ViewModel
-    public class Chat
+    public class Chat : INotifyPropertyChanged
     {
         public Action<Exception> ExceptionCallback { get; set; }
         public Action<Exception> ThreadExceptionCallback { get; set; }
@@ -451,7 +455,7 @@ namespace ChatController.HauptKlassen
             }
         }
 
-        public async void SendMessage(string message, long groupId)
+        public async Task SendMessage(string message, long groupId)
         {
             try
             {
@@ -466,14 +470,12 @@ namespace ChatController.HauptKlassen
 
                     var httpRequest = new HttpRequestMessage {Method = HttpMethod.Post, RequestUri = requestUri, Content = multiPartContent};
 
-                    //wegen Kontent nachschauen 
                     httpRequest.Headers.Add("Token", ChatDaten.AuthToken);
                     httpRequest.Headers.Add("CustomerID", ChatDaten.Kundennummer);
 
                     var httpClient = new HttpClient();
                     await httpClient.SendAsync(httpRequest, CancellationToken.None).ConfigureAwait(false);
                 }
-               
             }
             catch (Exception exception)
             {
@@ -501,13 +503,13 @@ namespace ChatController.HauptKlassen
             }
         }
 
-        public List<ChatMessage> AddNewFile(string pathToFile, string originalFilePath, long groupId, ChatMessage previousMessage)
+        public List<ChatMessage> AddNewFile(string pathToScaledFile, string originalFilePath, long groupId, ChatMessage previousMessage)
         {
             var result = new List<ChatMessage>();
 
             try
             {
-                if (string.IsNullOrEmpty(pathToFile) || string.IsNullOrEmpty(originalFilePath))
+                if(string.IsNullOrEmpty(pathToScaledFile) || string.IsNullOrEmpty(originalFilePath))
                 {
                     return result;
                 }
@@ -516,10 +518,10 @@ namespace ChatController.HauptKlassen
 
                 var sendTime = DateTime.Now;
 
-                if (Constants.ImageFileExtensions.Contains(Path.GetExtension(pathToFile).ToUpperInvariant()))
+                if (Constants.ImageFileExtensions.Contains(Path.GetExtension(pathToScaledFile).ToUpperInvariant()))
                 {
                     byte[] file;
-                    using (Stream reader = File.OpenRead(pathToFile))
+                    using (Stream reader = File.OpenRead(pathToScaledFile))
                     {
                         file = Utils.ReadFully(reader);
                     }
@@ -558,7 +560,8 @@ namespace ChatController.HauptKlassen
                                 bitmapImage.EndInit();
                                 bitmapImage.Freeze();
 
-                                var chatMessage = new ChatMessage(groupId, 0, ChatDaten.LoggedInUser.Response.User.UserName, Path.GetFileName(pathToFile), sendTime, true, memoryStream.Length, null, pathToFile, Path.GetFileName(pathToFile), null, bitmapImage, ChatMessageType.Image, ChatDaten.LoggedInUser.Response.User.Oid);
+                                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);
                             }
                         }
@@ -568,7 +571,7 @@ namespace ChatController.HauptKlassen
                 {
                     var linkToThumbnail = $"{ChatDaten.ServerUrl}/document.png";
 
-                    var chatMessage = new ChatMessage(groupId, 0, ChatDaten.LoggedInUser.Response.User.UserName, Path.GetFileName(pathToFile), sendTime, true, 0, pathToFile, null, null, linkToThumbnail, null, ChatMessageType.Document, ChatDaten.LoggedInUser.Response.User.Oid);
+                    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);
                 }
 
@@ -628,11 +631,11 @@ namespace ChatController.HauptKlassen
             return AddSeparators(result);
         }
 
-        public void SendFileToContact(Contact currentContact, string pFile, string pOriginalFilePath)
+        public async Task SendFileToContact(Contact currentContact, string scaledImagePath, string originalFilePath, string message)
         {
             try
-            {             
+            {
-                SendFile(pFile, currentContact, pOriginalFilePath);   
+                await SendFile(scaledImagePath, currentContact, originalFilePath, message);
             }
             catch (Exception exception)
             {
@@ -641,7 +644,7 @@ namespace ChatController.HauptKlassen
         }
 
         // WebRequest                                                                                                                                                                            
-        private void SendFile(string pFile, Contact currentContact, string pOriginalFilePath)
+        private async Task SendFile(string pFile, Contact currentContact, string pOriginalFilePath, string message)
         {
             if(string.IsNullOrEmpty(pOriginalFilePath))
             {
@@ -660,18 +663,18 @@ namespace ChatController.HauptKlassen
             { 
                 fileName = fileName.Replace(".bmp", ".jpg");
 
-                SendMediaMessage(fileName, currentContact.GroupId, mediaFile);
+                await SendMediaMessage(fileName, currentContact.GroupId, mediaFile, message);
             }
             else
             {
-                SendMediaMessage(fileName, currentContact.GroupId, mediaFile);
+                await SendMediaMessage(fileName, currentContact.GroupId, mediaFile, message);
             }
         }
         
         private HttpRequestMessage _HttpRequest;
 
         // WebRequest
-        private async void SendMediaMessage(string pMessage, long pGroupId, byte[] pMediaFile)
+        private async Task SendMediaMessage(string fileName, long groupId, byte[] mediaFile, string message)
         {
             try
             {
@@ -679,8 +682,13 @@ namespace ChatController.HauptKlassen
                 {
                     var requestUri = new Uri(ChatDaten.ServerUrl + Constants.SendMessageUrl);
 
-                    multiPartContent.Add(new ByteArrayContent(pMediaFile, 0, pMediaFile.Length), "file", pMessage);
+                    multiPartContent.Add(new ByteArrayContent(mediaFile, 0, mediaFile.Length), "file", fileName);
-                    multiPartContent.Add(new StringContent(pGroupId.ToString()), "groupid");
+                    multiPartContent.Add(new StringContent(groupId.ToString()), "groupid");
+
+                    if(!string.IsNullOrWhiteSpace(message))
+                    {
+                        multiPartContent.Add(new StringContent(message), "text");
+                    }
 
                     _HttpRequest = new HttpRequestMessage
                     {
@@ -693,7 +701,7 @@ namespace ChatController.HauptKlassen
                     _HttpRequest.Headers.Add(Constants.CustomerId, ChatDaten.Kundennummer);
 
                     var httpClient = new HttpClient();
-                    var httpResponse = await httpClient.SendAsync(_HttpRequest, CancellationToken.None).ConfigureAwait(false);
+                    var httpResponse = await httpClient.SendAsync(_HttpRequest, CancellationToken.None);//.ConfigureAwait(false);
 
                     var antwortResponse = await httpResponse.Content.ReadAsStringAsync();
                 }
@@ -800,7 +808,7 @@ namespace ChatController.HauptKlassen
             }
         }
 
-        public void Paste(long pGroupOid, ChatMainControl pChatMainControl)
+        public async Task Paste(long pGroupOid, ChatMainControl pChatMainControl)
         {         
             var dataObject = Clipboard.GetDataObject();
 
@@ -828,7 +836,7 @@ namespace ChatController.HauptKlassen
                             pChatMainControl.ChatListBox.Items.MoveCurrentToLast();
                             pChatMainControl.ChatListBox.ScrollIntoView(pChatMainControl.ChatListBox.Items.CurrentItem);
 
-                            SendMediaMessage(fileName, pGroupOid, mediaFile);
+                            await SendMediaMessage(fileName, pGroupOid, mediaFile, null);
                         }
                     }
                 }
@@ -850,7 +858,7 @@ namespace ChatController.HauptKlassen
                     pChatMainControl.ChatListBox.Items.MoveCurrentToLast();
                     pChatMainControl.ChatListBox.ScrollIntoView(pChatMainControl.ChatListBox.Items.CurrentItem);
 
-                    SendMessage(text, pGroupOid);
+                    await SendMessage(text, pGroupOid);
                 }
                 else if (dataObject.GetDataPresent(DataFormats.Bitmap))
                 {
@@ -867,7 +875,7 @@ namespace ChatController.HauptKlassen
                     pChatMainControl.ChatListBox.Items.MoveCurrentToLast();
                     pChatMainControl.ChatListBox.ScrollIntoView(pChatMainControl.ChatListBox.Items.CurrentItem);
 
-                    SendMediaMessage(imageName, pGroupOid, Utils.ImageToByteArray(image));
+                    await SendMediaMessage(imageName, pGroupOid, Utils.ImageToByteArray(image), null);
                 }
                 else
                 {
@@ -1189,6 +1197,34 @@ namespace ChatController.HauptKlassen
                 ExceptionCallback?.Invoke(exception);
             }
         }
+
+        private bool _IsInBroadcastMode;
+
+        public bool IsInBroadcastMode
+        {
+            get => _IsInBroadcastMode;
+            set
+            {
+                _IsInBroadcastMode = value;
+                OnPropertyChanged(nameof(IsInBroadcastMode));
+            }
+        }
+
+        public void SendBroadcastMessage()
+        {
+            throw new NotImplementedException("SendBroadcastMessage implementieren!");
+        }
+
+
+
+
+        public event PropertyChangedEventHandler PropertyChanged;
+
+        [NotifyPropertyChangedInvocator]
+        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
+        {
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+        }
     }
 
     public class ChatMessageComparer : IComparer

ChatController/LoginControl.xaml

@@ -53,21 +53,21 @@
                     <Button FontSize="15" Grid.ColumnSpan="2" Grid.Column="0" Grid.Row="5" VerticalContentAlignment="Center" Click="AnmeldenButton_OnClick" Content="Anmelden" HorizontalAlignment="Right" VerticalAlignment="Center" Margin="3" Width="100" Height="40" Background="#ff5e00" HorizontalContentAlignment="Center" >
                         <Button.Style>
                             <Style TargetType="{x:Type Button}">
-                                <Setter Property="BorderBrush" Value="#ff5e00" />
+                                <Setter Property="BorderBrush" Value="#FF5A00" />
-                                <Setter Property="Background" Value="#ff5e00" />
+                                <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="#ff5300" CornerRadius="5" Padding="1">
+                                            <Border x:Name="Border" Background="#FF5A00" CornerRadius="5" Padding="1">
                                                 <ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center" />
                                             </Border>
                                             <ControlTemplate.Triggers>
                                                 <Trigger Property="IsMouseOver" Value="True">
-                                                    <Setter Property="Background" Value="#ff9999" TargetName="Border" />
+                                                    <Setter Property="Background" Value="#FF988F" TargetName="Border" />
                                                 </Trigger>
                                                 <Trigger Property="IsPressed" Value="True">
-                                                    <Setter Property="Background" Value="#ff3a00" TargetName="Border" />
+                                                    <Setter Property="Background" Value="#FF7654" TargetName="Border" />
                                                 </Trigger>
                                             </ControlTemplate.Triggers>
                                         </ControlTemplate>

ChatController/Utilities/BroadcastMessage.cs

@@ -0,0 +1,68 @@
+using System;
+using System.ComponentModel;
+using System.IO;
+using System.Runtime.CompilerServices;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using ChatController.Annotations;
+
+namespace ChatController.Utilities
+{
+    public class BroadcastMessage : INotifyPropertyChanged
+    {
+        private string _OriginalFilePath;
+        public string OriginalFilePath
+        {
+            get => _OriginalFilePath;
+            set
+            {
+                _OriginalFilePath = value;
+                OnPropertyChanged(nameof(OriginalFilePath));
+            }
+        }
+
+        private string _ScaledFilePath;
+        public string ScaledFilePath
+        {
+            get => _ScaledFilePath;
+            set
+            {
+                _ScaledFilePath = value;
+                OnPropertyChanged(nameof(ScaledFilePath));
+            }
+        }
+
+        private ImageSource _BroadcastMessageImageSource;
+
+        public ImageSource BroadcastMessageImageSource
+        {
+            get => _BroadcastMessageImageSource;
+            set
+            {
+                _BroadcastMessageImageSource = value;
+                OnPropertyChanged(nameof(BroadcastMessageImageSource));
+            }
+        }
+
+        public BroadcastMessage(string originalFilePath, string scaledFilePath)
+        {
+            OriginalFilePath = originalFilePath;
+            ScaledFilePath = scaledFilePath;
+
+            var bitmap = new BitmapImage();
+            bitmap.BeginInit();
+            bitmap.UriSource = new Uri(scaledFilePath);
+            bitmap.EndInit();
+
+            BroadcastMessageImageSource = bitmap;
+        }
+
+        public event PropertyChangedEventHandler PropertyChanged;
+
+        [NotifyPropertyChangedInvocator]
+        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
+        {
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+        }
+    }
+}

ChatController/Utilities/BroadcastProgressReportModel.cs

@@ -0,0 +1,7 @@
+namespace ChatController.Utilities
+{
+    public class BroadcastProgressReportModel
+    {
+        public int PercentageComplete { get; set; } = 0;
+    }
+}

ChatController/Utilities/Extensions/ObservableSortCollection.cs

@@ -0,0 +1,105 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Collections.Specialized;
+using System.Linq;
+
+namespace ChatController.Utilities.Extensions
+{
+    public class ObservableSortCollection<T> : ObservableCollection<T>
+    {
+        private readonly List<NotifyCollectionChangedEventHandler> _ChangedHandler = new List<NotifyCollectionChangedEventHandler>();
+
+        private readonly Comparison<T> _Comparer;
+
+        public ObservableSortCollection()
+        {
+        }
+
+        public ObservableSortCollection(IEnumerable<T> pList) : base(pList.ToList())
+        {
+        }
+
+        public ObservableSortCollection(Comparison<T> pComparer) : this()
+        {
+            _Comparer = pComparer;
+            Sort();
+        }
+
+        public ObservableSortCollection(IEnumerable<T> pList, Comparison<T> pComparer) : this(pList)
+        {
+            _Comparer = pComparer;
+            Sort();
+        }
+
+        public override event NotifyCollectionChangedEventHandler CollectionChanged
+        {
+            add
+            {
+                _ChangedHandler.Add(value);
+                base.CollectionChanged += value;
+            }
+
+            remove
+            {
+                _ChangedHandler.Remove(value);
+                base.CollectionChanged -= value;
+            }
+        }
+
+        public void Sort()
+        {
+            if (_Comparer != null)
+            {
+                DisconnectHandler();
+                var lTemp = this.ToList();
+                lTemp.Sort(_Comparer);
+                for (var i = 0; i < Count; i++)
+                {
+                    this[i] = lTemp[i];
+                }
+
+                ReconnectHandler();
+                NotifyHandlerAfterSort();
+            }
+        }
+
+        public void Sort(Comparison<T> pComparer)
+        {
+            DisconnectHandler();
+            var lTemp = this.ToList();
+            lTemp.Sort(pComparer);
+            for (var i = 0; i < Count; i++)
+            {
+                this[i] = lTemp[i];
+            }
+
+            ReconnectHandler();
+            NotifyHandlerAfterSort();
+        }
+
+        private void DisconnectHandler()
+        {
+            foreach (var iHandler in _ChangedHandler)
+            {
+                base.CollectionChanged -= iHandler;
+            }
+        }
+
+        private void NotifyHandlerAfterSort()
+        {
+            foreach (var iHandler in _ChangedHandler)
+            {
+                iHandler(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
+            }
+        }
+
+        private void ReconnectHandler()
+        {
+            foreach (var iHandler in _ChangedHandler)
+            {
+                base.CollectionChanged += iHandler;
+            }
+        }
+    }
+}

ChatController/Utilities/ListItemHelper.cs

@@ -0,0 +1,19 @@
+using System.Windows;
+
+namespace ChatController.Utilities
+{
+    public class ListItemHelper : DependencyObject
+    {
+        public static readonly DependencyProperty IsCheckedProperty = DependencyProperty.RegisterAttached("IsChecked", typeof(bool?), typeof(ListItemHelper), new PropertyMetadata(false, null));
+
+        public static void SetIsChecked(DependencyObject element, bool? IsChecked)
+        {
+            element.SetValue(IsCheckedProperty, IsChecked);
+        }
+
+        public static bool? GetIsChecked(DependencyObject element)
+        {
+            return (bool?)element.GetValue(IsCheckedProperty);
+        }
+    }
+}

ChatController/Utilities/Utils.cs

@@ -14,11 +14,14 @@ 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
 {

PrototypChat/MainWindow.xaml

@@ -5,6 +5,7 @@
         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"
         Title="ownChat Desktop" Height="700" Width="900" x:Name="MainView" Closed="MainWindow_OnClosed">
     <Grid>
         <cc:ChatMainControl x:Name="ChatMainControl" OnEmojii="ChatMainControl_OnOnEmojii"></cc:ChatMainControl>

PrototypChat/MainWindow.xaml.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using System.Threading;
 using System.Windows;
 
@@ -49,5 +50,10 @@ namespace ownChat
 
             Environment.Exit(0);
         }
+
+        private void MainWindow_OnSizeChanged(object sender, SizeChangedEventArgs e)
+        {
+            Debug.WriteLine($"+++>ActualHeight: {ActualHeight}");
+        }
     }
 }