NRE on Android when a new activity is opened

This issue has been observed on Android 9 and 10 The problem exists on the current master branch as well as v7.2.1046

The issue is reproducible in the sample app that is part of this project too. I have attached a video showing steps to reproduce the issue along with the code I modified to log the exception.

Essentially Android creates a new activity which I expect should return the app to the initial page. I have also tried creating this scenario with Xamarin Forms and Rg.Plugins.Popup (without Prism). In this case, the navigation seems to work fine.

System.NullReferenceException: Object reference not set to an instance of an object.
  at Prism.Common.PageUtilities.GetCurrentPage (Xamarin.Forms.Page mainPage) [0x00002] in /_/src/Forms/Prism.Forms/Common/PageUtilities.cs:255 
  at Prism.Plugin.Popups.PopupPageNavigationService.DoPush (Xamarin.Forms.Page currentPage, Xamarin.Forms.Page page, System.Nullable`1[T] useModalNavigation, System.Boolean animated, System.Boolean insertBeforeLast, System.Int32 navigationOffset) [0x00218] in 

Screen Recording 2020-09-24 at 2.51.09 PM.mov.zip

samples.zip

[pravincar]

@jbachelor I’ve seen the problem that you have described in some scenarios too. However, it is different from the issue I have reported here. I have implemented a workaround in my app to get rid of the Task.Delay.

Create a popup pop observable which subscribes to the PopupNavigation instance in Rg.Plugins.Popup

public IObservable<System.Reactive.EventPattern<PopupNavigationEventArgs>> PopupPopObservable
            = Observable.FromEventPattern<PopupNavigationEventArgs>(
                (h) => PopupNavigation.Instance.Popped += h, (h) => PopupNavigation.Instance.Popped -= h);

Wait for the popup to get cleared before any further navigation

await PopupPopObservable.Take(1);

This may work for you too.

[dansiegel]

@pravincar as this has been reported by both @jbachelor and @jdarmody as not happening anymore I’m going to close the issue. If it continues to please let me know and we’ll reopen the issue.