Xamarin.forms: [iOS] OnAppearing not firing when returning to app

[hartez]

Description

Manual test for 52318 does not match the test instructions. Specifically, the test says "Only the last page should alert" when the app is reactivated after hitting the Home button. But currently _no alert_ displays when reactivating the app.

We need to determine if this is a regression or simply incorrect test instructions.

Original bug: https://bugzilla.xamarin.com/show_bug.cgi?id=52318

Steps to Reproduce

1. Open the Control Gallery.
2. Navigate to issue 52318
3. Follow the test instructions.

Expected Behavior

Instructions match the behavior of the app.

Actual Behavior

The app displays different behavior than the instructions.

Basic Information

• Version with issue: 3.5.0
• Last known good version: 2.3.5, assuming the instructions are correct.

[hartez]

See also #1874.

[hartez]

Android also does not alert when the app is reactivated.

[adrianknight89]

iOS page events are messed up. Also see #4608.

[ghost]

This is a vote +1 to change here please something.

In my case following is happening. iOS 12.1.3 physical device, iPhone X.
Start your app, stay on master detail, detail page (top of stack). Press power button, OnResignActivation, OnSleep was called, DidEnterBackground is called on AppDelegate.

If you resume the device, pressing power button and unlock device. App is still in foreground.
OnActivated AppDelegate, OnResume App.Xaml.cs is called but not OnAppearing of master detail detail page. I guess _hasAppeared flag does prevent this or SendAppearing is never called.

So solution can be - SendDisappearing and SendAppearing should be triggered in OnSleep/OnResume respectively?

Xamarin forms version is - 3.4.0.1.029999.
(not to mention that android does call OnAppearing of the current visible master detail detail page)

[ganesanvelusamy]

+1

I'm also facing the same issue.

[jorgeperalta]

Is this problem solved? I'm experiencing the same issue with xamarin forms 4.1.0.673156. Please answer.

[JanWidm]

Still experiencing this Problem. Only in iOS 13. Newer versions of iOS work fine and all versions I tested in Android work fine too! Any help?

[larsduewel]

Still is a problem sadly.

[JanWidm]

@larsduewel Posted my question on xamarin forums, maybe this could help you https://forums.xamarin.com/discussion/174412/xamarin-forms-ios-13-onappearing-not-called-after-i-navigate-back-from-platform-specific-code#latest

[Savage1024]

I found a workaround https://kent-boogaart.com/blog/hacking-xamarin.forms-page.appearing-for-ios
But I don’t understand how to apply it to NavigationPage