Task RunWindowTest <THandler>(IWindow window, Func <THandler, Task> action) where THandler : class, IElementHandler { return(InvokeOnMainThreadAsync(async() => { var testingRootPanel = (WPanel)MauiProgram.CurrentWindow.Content; IElementHandler newWindowHandler = null; NavigationRootManager navigationRootManager = null; try { var scopedContext = new MauiContext(MauiContext.Services); scopedContext.AddWeakSpecific(MauiProgram.CurrentWindow); var mauiContext = scopedContext.MakeScoped(true); navigationRootManager = mauiContext.GetNavigationRootManager(); navigationRootManager.UseCustomAppTitleBar = false; newWindowHandler = window.ToHandler(mauiContext); var content = window.Content.Handler.ToPlatform(); await content.OnLoadedAsync(); await Task.Delay(10); if (typeof(THandler).IsAssignableFrom(newWindowHandler.GetType())) { await action((THandler)newWindowHandler); } else if (typeof(THandler).IsAssignableFrom(window.Content.Handler.GetType())) { await action((THandler)window.Content.Handler); } } finally { if (navigationRootManager != null) { navigationRootManager.Disconnect(); } if (newWindowHandler != null) { newWindowHandler.DisconnectHandler(); } // Set the root window panel back to the testing panel if (testingRootPanel != null && MauiProgram.CurrentWindow.Content != testingRootPanel) { MauiProgram.CurrentWindow.Content = testingRootPanel; await testingRootPanel.OnLoadedAsync(); await Task.Delay(10); } } })); }