ChatRoomChoise.xaml

<Window x:Class="ChatRoomProject.ChatRoomChoise"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
        xmlns:local="clr-namespace:ChatRoomProject"
        mc:Ignorable="d"
        Title="ChatRoomChoise" Height="450" Width="800" WindowStyle="None" ResizeMode="NoResize" Topmost="True">
    <Grid>

        <!-- Nouveau background de l'application, linear background purple to green -->
        <Grid.Background>
            <LinearGradientBrush StartPoint="0.1,0" EndPoint="0.9,1">
                <GradientStop Color="#1D8348" Offset="1" />
                <GradientStop Color="#8E44AD" Offset="0" />
            </LinearGradientBrush>
        </Grid.Background>

        <!-- Bordure inférieur, réalisé avec un gradient de couleur-->
        <Border Height="390" VerticalAlignment="Top" CornerRadius="0 0 180 0" Background="#100E17" MouseDown="Border_MouseDown"></Border>

        <!-- Bouton de fermeture d'application -->
        <StackPanel Width="100" Margin="700,0,0,0">
            <Button Margin="22,20" Style="{StaticResource MaterialDesignFloatingActionButton}" Background="{x:Null}"
                 ToolTip="Close" x:Name="btnExit" Click="btnExit_Click">
                <materialDesign:PackIcon Kind="Close" Foreground="White" Width="30" Height="30" />
            </Button>
        </StackPanel>

        <!-- Creation Panel Chat Room -->
        <TextBlock Text="Création ChatRoom" Margin="-18,66,454,339" Foreground="White" TextAlignment="Center" FontSize="30" FontFamily="Tahoma"/>
        <StackPanel Orientation="Horizontal" Margin="35,172,515,247">
            <materialDesign:PackIcon Kind="Forum" Width="25" Height="25" Foreground="White"/>
            <TextBox x:Name="NewChatRoomName"  Margin="10 0" materialDesign:HintAssist.Hint="Nom de la nouvelle ChatRoom à créer" Foreground="White" Width="250" BorderBrush="White" CaretBrush="#FFD94448" SelectionBrush="#FFD94448"/>
        </StackPanel>
        <Button x:Name="Creationbutton"  Content="Valider Création" Height="Auto" Margin="54,225,527,189" Click="btnCreationbutton_Click"/>

        <!-- Join Chat Room Panel-->
        <TextBlock Text="Rejoindre une ChatRoom" Margin="361,65,75,340" Foreground="White" TextAlignment="Center" FontSize="30" FontFamily="Tahoma"/>
        <Expander  Margin="371,122,74,108" Background="#1D8348 " Cursor="Cross" IsExpanded="True" RenderTransformOrigin="0.5,0.5" BorderBrush="Azure" BorderThickness="5">
            <Expander.Header >
                <TextBlock Foreground="#100E17"  xml:space="preserve" Margin="0,0,0,0" Height="21" Canvas.Top="-10" FontWeight="Bold" TextDecorations="Underline">Liste des Rooms disponibles :</TextBlock>
            </Expander.Header>
            <StackPanel Name="InsertionPlace"></StackPanel>
        </Expander>

    </Grid>
</Window>