MAUI: Issue with displaying Flyout menu page

Hello @Sreenivasan, Sreejith ,

The problem you're experiencing occurs because the flyout state and tab selection are getting out of sync.

Xamarin.Forms was more lenient with these state changes, but MAUI enforces stricter synchronization.

The issue stems from several factors:

1. Your menuIsOpen boolean is not properly synchronized with the actual flyout presentation state
2. Subscribing/unsubscribing to IsPresentedChanged on every toggle creates timing issues
3. Changing CurrentPage while the flyout is presenting can cause race conditions in MAUI

Since I cannot see the full details, please use this as a reference for your implementation.

public partial class DashboardTabPage : TabbedPage
{
    private int _lastSelectedTabIndex = 0;
    private bool _isProcessingMenuToggle = false;
    private FlyoutPage _flyoutPage;
 
    public DashboardTabPage()
    {
        InitializeComponent();
        InitializeFlyoutHandling();
    }
 
    private void InitializeFlyoutHandling()
    {
        _flyoutPage = MainService.HomePage.Value as FlyoutPage;
       
        if (_flyoutPage == null)
        {
            throw new InvalidOperationException("HomePage must be a FlyoutPage");
        }
       
        _flyoutPage.IsPresentedChanged += OnFlyoutPresentedChanged;
    }
 
    private void OnFlyoutPresentedChanged(object sender, EventArgs e)
    {
        if (_isProcessingMenuToggle) return;
 
        var flyoutPage = (FlyoutPage)sender;
       
        // Reset tab selection when flyout closes externally (tap outside)
        if (!flyoutPage.IsPresented && IsCurrentPageMenuTab())
        {
            Device.BeginInvokeOnMainThread(() =>
            {
                _isProcessingMenuToggle = true;
                CurrentPage = Children[_lastSelectedTabIndex];
                _isProcessingMenuToggle = false;
            });
        }
    }
 
    void HandleCurrentPageChanged(object sender, EventArgs e)
    {
        if (_isProcessingMenuToggle) return;
 
        var currentIndex = Children.IndexOf(CurrentPage);
       
        if (!IsCurrentPageMenuTab())
        {
            _lastSelectedTabIndex = currentIndex;
            return;
        }
 
        HandleMenuTabTap();
    }
 
    private async void HandleMenuTabTap()
    {
        if (_flyoutPage == null) return;
 
        _isProcessingMenuToggle = true;
 
        if (_flyoutPage.IsPresented)
        {
            _flyoutPage.IsPresented = false;
            await Task.Delay(50);
            CurrentPage = Children[_lastSelectedTabIndex];
        }
        else
        {
            _flyoutPage.IsPresented = true;
        }
 
        _isProcessingMenuToggle = false;
    }
 
    private bool IsCurrentPageMenuTab()
    {
        return CurrentPage?.GetType() == NavigationService.GetPageType<AppMenuViewModel>();
    }
 
    protected override void OnDisappearing()
    {
        base.OnDisappearing();
       
        if (_flyoutPage != null)
        {
            _flyoutPage.IsPresentedChanged -= OnFlyoutPresentedChanged;
        }
    }
}

Testing Recommendations:

1. Test the flyout behavior on different platforms (iOS/Android)
2. Verify that the tab color resets properly when flyout closes
3. Ensure smooth animation without flickering
4. Test rapid tapping scenarios

I hope this helps. Let me know if you have any other questions.