MAUI Window Position and Size (WinUI3 and MacCatalyst)

Example_A.MauiProgram.cs

// ******** WinUI3 Window management ******** //
using Microsoft.Maui.LifecycleEvents;

#if WINDOWS
using Microsoft.UI;
using Microsoft.UI.Windowing;
using Windows.Graphics;
#endif

namespace MyApp.Maui
{
    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 =>
            {
                events.AddWindows(wndLifeCycleBuilder =>
                {
                    wndLifeCycleBuilder.OnWindowCreated(window =>
                    {
                        // Hard coded logic to center window on a 1920x1080 display, adjust as needed
                        const int width = 1200;
                        const int height = 800;
                        const int x = 1920 / 2 - width / 2;
                        const int y = 1080 / 2 - height / 2;

                        window.MoveAndResize(new RectInt32(x, y, width, height));
                    });
                });
            });
#endif

            return builder.Build();
        }
    }
}

Example_B.MauiProgram.cs

// ******** MacCatalyst Window management ******** //

using Microsoft.Maui.LifecycleEvents;

#elif MACCATALYST
using AppKit;
using CoreGraphics;
using Foundation;
using UIKit;

#endif


namespace Hacked.Maui
{
    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");
                });


            builder.ConfigureLifecycleEvents(events =>
            {
#elif MACCATALYST
                
                events.AddiOS(wndLifeCycleBuilder =>
                {
                    wndLifeCycleBuilder.SceneWillConnect((scene, session, options) =>
                    {
                        if (scene is UIWindowScene { SizeRestrictions: { } } windowScene)
                        {
                            windowScene.SizeRestrictions.MaximumSize = new CGSize(1200, 900);
                            windowScene.SizeRestrictions.MinimumSize = new CGSize(600, 400);
                        }
                    });

                });
#endif
            });


            return builder.Build();
        }
    }
}

@faisalkkv woot! Just in case it's helpful, I have checked in a full example in one of my demo repositories.

• See here for the extension method's use https://github.com/LanceMcCarthy/DevOpsExamples/blob/main/src/MAUI/MauiDemo/MauiProgram.cs
• See here for the required NuGet package https://github.com/LanceMcCarthy/DevOpsExamples/blob/ccc975c8da1999b16cc64b690d857ff8dec6e920/src/MAUI/MauiDemo/MauiDemo.csproj#L69