BeWoPlaner/BeWo/UploadDialog.xaml

<Window x:Class="BeWo.UploadDialog"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="UploadDialog" Height="150" Width="300"
        WindowStartupLocation="CenterOwner"
        WindowStyle="None"
        AllowsTransparency="True"
        Background="Transparent" ResizeMode="NoResize" >
    <Grid>
        <GroupBox Style="{DynamicResource MainContentGroupBoxWithoutMaximizeBtnStyle}" Header="Download" MouseLeftButtonDown="UIElement_OnMouseLeftButtonDown">
            <Grid Background="{DynamicResource ObjectEditBackgroundBrush}">
                <Grid.RowDefinitions>
                    <RowDefinition Height="*" />
                    <RowDefinition Height="Auto" />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*" />
                    <ColumnDefinition Width="Auto" />
                    <ColumnDefinition Width="Auto" />
                </Grid.ColumnDefinitions>
                <TextBlock Margin="3" Text="{Binding Question}" Grid.ColumnSpan="3" HorizontalAlignment="Center" VerticalAlignment="Center" TextWrapping="Wrap" TextAlignment="Center" Foreground="#FF202020"/>
                <Button Margin="0,0,5,5" Grid.Row="1" Grid.Column="1" Content="Hochladen" Click="btn_Upload_Click" x:Name="Hochladebtn" />
                <Button Margin="0,0,5,5" Grid.Row="1" Grid.Column="2" Content="Abbrechen" Command="Close" x:Name="Abbrechbtn" />
            </Grid>
        </GroupBox>
    </Grid>
</Window>