Onappearing not working when modal page is popped in Xamarin iOS

Question

I have an onappearing method which doesn't fire when page is popped in Xamarin iOS but works fine in Xamarin Android.Could anyone please help me with this. Thank you.

Page 1 (Tabbed Page)

 protected override void OnAppearing()
    {
        base.OnAppearing();

            if (CVItems.SelectedItem != null)
                CVItems.SelectedItem = null;
    }

    private async void CVItems_SelectionChangedAsync(object sender, SelectionChangedEventArgs e)
    {
        var selecteditem = e.CurrentSelection.First() as Item;
        var detailPage = new AdPage(selecteditem);
        detailPage.BindingContext = selecteditem;
        await Navigation.PushModalAsync(detailPage);             
    }

Page 2 (Modal Page)

    private async void poppage_Tapped(object sender, EventArgs e)
    {
        await Navigation.PopModalAsync();
    }

When an item in collection view is tapped, modal page opens up and then when I pop back to the tabbed page, the onappearing() method is not triggered.

Answer 1

Please could you show an example of you code?

You could try the following try catch to view any error that is happening:

public void OnAppearing() //could add a protected override
{
            try
            {
                OnAppearing();

            }
            catch (Exception Ex)
            {
                Debug.WriteLine(Ex.Message);
            }
}

Answer 2

You could have a tru wtih updating the version of Xamarin Forms to the latest version to check whether it works.

I have checked in the latest version of Xamarin Forms( 5.0.0.1931 ) and iOS( 14.4 ), it works as expected no matter TabbedPage or ContentPage (Child page of TabbedPage).

Based on this offical sample to modify code to test.

• Step one: Press OnUpcomingAppointments Button to next Page.

• Step two: Press Back button then back to SchedulePage .

TabbedPage :

public partial class MainPage : TabbedPage
{
    public MainPage ()
    {
        InitializeComponent ();
    }

    protected override void OnAppearing()
    {
        base.OnAppearing();
        Console.WriteLine("TabbedPage OnAppearing");
    }
}

SchedulePage :

public partial class SchedulePage : ContentPage
{
    public SchedulePage ()
    {
        InitializeComponent ();
    }

    async void OnUpcomingAppointmentsButtonClicked (object sender, EventArgs e)
    {
        await Navigation.PushModalAsync (new UpcomingAppointmentsPage ());
    }

    protected override void OnAppearing()
    {
        base.OnAppearing();
        Console.WriteLine("SchedulePage OnAppearing");
    }
}

The output:

2021-02-12 11:03:03.800726+0800 TabbedPageWithNavigationPageiOS[5537:75334] TabbedPage OnAppearing
2021-02-12 11:03:03.801024+0800 TabbedPageWithNavigationPageiOS[5537:75334] SchedulePage OnAppearing