MainWindow.xaml

<Window x:Class="WpfWebviewApp.MainWindow"
        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:local="clr-namespace:WpfWebviewApp"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800"
        Loaded="Window_Loaded"
        Closing="Window_Closing">
    <Grid>
        <!-- Define rows for layout -->
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <!-- For buttons -->
            <RowDefinition Height="*" />
            <!-- For image display -->
        </Grid.RowDefinitions>

        <!-- Buttons in the first row -->
        <StackPanel Orientation="Horizontal" Grid.Row="0" Margin="5">
            <Label Height="28" Name="label1" VerticalAlignment="Top" Content="Select Source"/>
            <ComboBox Width="200" Height="23" Margin="10,3,0,0" Name="cbxSources" VerticalAlignment="Top"/>
            <Button Content="Scan" Click="btnScanToView_Click" Margin="5" />
            <Button Content="SaveAsPdf" Click="btnSaveAsPdf_Click" Margin="5" />
        </StackPanel>

        <!-- Image display area in the second row -->
        <Grid Grid.Row="1">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="150" />
                <!-- Thumbnail list -->
                <ColumnDefinition Width="*" />
                <!-- Main image display -->
            </Grid.ColumnDefinitions>

            <!-- Thumbnail list -->
            <ListBox x:Name="thumbnailList" Grid.Column="0" 
                     SelectionChanged="ThumbnailList_SelectionChanged"
                     ScrollViewer.VerticalScrollBarVisibility="Auto">
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <Border BorderBrush="Gray" BorderThickness="1" Margin="2">
                            <Image Source="{Binding}" Width="120" Height="120" Stretch="Uniform"/>
                        </Border>
                    </DataTemplate>
                </ListBox.ItemTemplate>
            </ListBox>

            <!-- Main image display -->
            <Border Grid.Column="1" BorderBrush="LightGray" BorderThickness="1" Margin="5">
                <ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto">
                    <Image x:Name="mainImage" Stretch="Uniform"/>
                </ScrollViewer>
            </Border>
        </Grid>
    </Grid>
</Window>