MainWindow.xaml

<Window x:Class="MP3Joiner.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MP3 Joiner" Height="600" Width="800"
         xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
        TextElement.Foreground="{DynamicResource MaterialDesign.Brush.Foreground}"
        Background="{DynamicResource MaterialDesign.Brush.Background}"
        TextElement.FontWeight="Regular"
        TextElement.FontSize="12"
        FontFamily="{materialDesign:MaterialDesignFont}"

        TextOptions.TextFormattingMode="Ideal"
        TextOptions.TextRenderingMode="Auto">
    <Grid Margin="10">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="2*"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="3*"/>
            <ColumnDefinition Width="1*"/>
        </Grid.ColumnDefinitions>

        <!-- Buttons for adding files -->
        <StackPanel Grid.Row="0" Grid.Column="0" Orientation="Horizontal" Margin="0,0,49,10" Grid.ColumnSpan="2">
            <Button x:Name="btnAddFiles" Width="146" Click="btnAddFiles_Click">Add MP3 Files</Button>
            <Button x:Name="btnClearFiles" Width="146" Click="btnClearFiles_Click" Margin="10,0,0,0">Clear List</Button>
            <!-- New button to join MP3 files -->
            <Button x:Name="btnJoinFiles" Width="146" Click="btnJoinFiles_Click" Margin="10,0,0,0">Join MP3 Files</Button>
            <Button x:Name="btnreadidv3tag" Width="146" Click="btnreadidv3tag_Click" Margin="10,0,0,0" Content="Read Id3 Tag"/>
        </StackPanel>

        <!-- ListBox for MP3 Files with Drag and Drop Functionality -->
        <ListBox x:Name="mp3FileList" Grid.Row="1" Grid.Column="0" AllowDrop="True" BorderThickness="1" BorderBrush="Black"
                 Style="{DynamicResource MaterialDesignListBox}"
                 PreviewMouseMove="mp3FileList_PreviewMouseMove" 
                 DragEnter="mp3FileList_DragEnter"
                 DragOver="mp3FileList_DragOver" 
                 Drop="mp3FileList_Drop" Background="#FFDEDEDE">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding}" />
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>

        <!-- Album Art Drop Area -->
        <Border x:Name="AlbumArtBorder" Grid.Row="1" Grid.Column="1" Background="LightGray" Margin="5,5,5,5" BorderThickness="0" BorderBrush="Black"
                Width="200" Height="200" HorizontalAlignment="Center" VerticalAlignment="Center" AllowDrop="True"
                DragEnter="AlbumArtBorder_DragEnter" Drop="AlbumArtBorder_Drop">
            <Grid>
                <!-- Image to display the album art -->
                <Image x:Name="imgAlbumArt" Stretch="Uniform" Width="200" Height="200"/>
                <!-- TextBlock visible initially and hidden after image drop -->
                <TextBlock x:Name="AlbumArtPlaceholder" Text="Drop Image Here" HorizontalAlignment="Center" VerticalAlignment="Center"
                           Foreground="Black" Background="Transparent" Opacity="0.7"/>
            </Grid>
        </Border>

        <!-- Metadata inputs (Artist, Track, etc.) -->
        <StackPanel Grid.Row="2" Grid.ColumnSpan="2" Orientation="Vertical" Margin="0, 10, 0, 0">
            <TextBlock Text="Track Name:" Width="87" HorizontalAlignment="Left" Style="{DynamicResource MaterialDesignBody1TextBlock}" />
            <TextBox x:Name="txtTrackName" Width="400" HorizontalAlignment="Left" Style="{DynamicResource MaterialDesignTextBox}" />

            <TextBlock Text="Artist Name:" Margin="0,10,0,0" Width="92" HorizontalAlignment="Left" Style="{DynamicResource MaterialDesignBody1TextBlock}" />
            <TextBox x:Name="txtArtistName" Width="400" HorizontalAlignment="Left" Style="{DynamicResource MaterialDesignTextBox}"/>

            <!-- Progress Bar -->
            <ProgressBar x:Name="progressBar" Height="20" Margin="0, 20, 0, 0" Minimum="0" Maximum="100" Style="{DynamicResource MaterialDesignLinearProgressBar}" />
        </StackPanel>
    </Grid>
</Window>