MainWindow.xaml

<?xml version="1.0" encoding="utf-8"?>
<Window
    x:Class="WinUI3_SwapChainPanel_DWriteCore.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:WinUI3_SwapChainPanel_DWriteCore"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <!--<StackPanel Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Center">
        <Button x:Name="myButton" Click="myButton_Click">Click Me</Button>
    </StackPanel>-->

    <Grid x:Name="mainGrid" >

        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto"></ColumnDefinition>
            <ColumnDefinition Width="*"></ColumnDefinition>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"></RowDefinition>
            <RowDefinition Height="*"></RowDefinition>
            <RowDefinition Height="Auto"></RowDefinition>
        </Grid.RowDefinitions>

        <StackPanel Orientation="Horizontal" Grid.Column="0" Grid.Row="0" HorizontalAlignment="Left" VerticalAlignment="Top">
            <!--<Button x:Name="myButton" Click="myButton_Click" Margin="10, 10, 0, 0" VerticalAlignment="Center" >Set font for text with shadow</Button>-->
            <TextBlock Margin="10, 10, 0, 0" VerticalAlignment="Center" >Font for shadowed text :</TextBlock>
            <TextBlock Margin="10, 10, 0, 0" VerticalAlignment="Center" >Custom fonts :</TextBlock>
            <ComboBox x:Name="FontListCustom" Width="300" Margin="10, 10, 0, 0" VerticalAlignment="Center"
                      SelectionChanged="FontListCustom_SelectionChanged"
                     ItemsSource="{x:Bind CustomFonts}">
                <ComboBox.ItemTemplate>
                    <DataTemplate x:DataType="local:Font">
                        <TextBlock FontFamily="{x:Bind FontFamilyPath}" FontSize="24" Text="{x:Bind Name}" />
                    </DataTemplate>
                </ComboBox.ItemTemplate>
            </ComboBox>
            <TextBlock Margin="10, 10, 0, 0" VerticalAlignment="Center" >System fonts :</TextBlock>
            <ComboBox x:Name="FontListSystem" Width="500" Margin="10, 10, 0, 0" VerticalAlignment="Center"
                      SelectionChanged="FontListSystem_SelectionChanged"
                      ItemsSource="{x:Bind SystemFonts}">
                <ComboBox.ItemTemplate>
                    <DataTemplate x:DataType="local:Font">
                        <TextBlock FontFamily="{x:Bind FontFamilyPath}" FontWeight="{x:Bind FontWeight}" FontStyle="{x:Bind Style}"
                                  FontStretch="{x:Bind Stretch}" FontSize="24" Text="{x:Bind Name}" />                       
                    </DataTemplate>
                </ComboBox.ItemTemplate>
            </ComboBox>
        </StackPanel>
        <SwapChainPanel x:Name="scp1" Grid.Column="0" Grid.Row="1" Grid.ColumnSpan="2" Margin="10, 10, 10, 10"
                        HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
                        RenderTransformOrigin="0.5 0.5" >

            <!--Width ="800" Height="400"-->
            <!--HorizontalAlignment="Center" VerticalAlignment="Center"-->

            <!--<SwapChainPanel.RenderTransform>
                <ScaleTransform ScaleY="1" ScaleX="1" />
                -->
            <!--<ScaleTransform ScaleY="1.25" ScaleX="1.25" />-->
            <!--
            </SwapChainPanel.RenderTransform>-->
        </SwapChainPanel>

    </Grid>
</Window>