Use the new Windows App SDK Backdrop API in .NET MAUI

MauiProgram.cs

using Microsoft.Extensions.Logging;
using Microsoft.Maui.LifecycleEvents;
#if WINDOWS
using Microsoft.UI.Xaml.Media;
#endif

namespace MauiApp1;

public static class MauiProgram
{
	public static MauiApp CreateMauiApp()
	{
		var builder = MauiApp.CreateBuilder();
		builder
			.UseMauiApp<App>()
			.ConfigureFonts(fonts =>
			{
				fonts.AddFont("OpenSans-Regular.ttf", "OpenSansRegular");
				fonts.AddFont("OpenSans-Semibold.ttf", "OpenSansSemibold");
			});

#if WINDOWS
        builder.ConfigureLifecycleEvents(events =>
		{
			// Make sure to add "using Microsoft.Maui.LifecycleEvents;" in the top of the file 
			events.AddWindows(windowsLifecycleBuilder =>
			{
				windowsLifecycleBuilder.OnWindowCreated(window =>
				{
					window.SystemBackdrop = new DesktopAcrylicBackdrop();
				});
			});
		});
#endif

#if DEBUG
        builder.Logging.AddDebug();
#endif

		return builder.Build();
	}
}