[BUG] Xamarin Forms repeated TabNavigation causes app to slow and eventually lock

[lackrin]

Describe the bug When implementing Xamarin Forms Tab Navigation, where each tab is a page with its own navigation, the app will quickly start to Slow down on navigations, where the first navigation will be instant, but the 5th will take seconds.

Steps To Reproduce Provide the steps to reproduce the behavior: setup a tab page with each tab having its own routedviewhost

            var homeDashboardView = Locator.CurrentMutable.GetService<DashboardViewModel>();
            homeDashboardView.Router.NavigateAndReset.Execute(homeDashboardView).Subscribe();
            Locator.CurrentMutable.RegisterConstant(homeDashboardView, typeof(IScreen));
            hostDashboardView = new RoutedViewHost { Router = homeDashboardView.Router, Title = "\uf0b1 Jobs" };

            var homeMapView = Locator.CurrentMutable.GetService<MapViewModel>();
            homeMapView.Router.Navigate.Execute(homeMapView).Subscribe();
            Locator.CurrentMutable.RegisterConstant(homeMapView, typeof(IScreen));
            hostMapView = new RoutedViewHost { Router = homeMapView.Router, Title = "\uf279 Map" };

            var homeDocumentsView = Locator.CurrentMutable.GetService<DocumentsViewModel>();
            homeDocumentsView.Router.Navigate.Execute(homeDocumentsView).Subscribe();
            Locator.CurrentMutable.RegisterConstant(homeDocumentsView, typeof(IScreen));
            hostDocumentsView = new RoutedViewHost { Router = homeDocumentsView.Router, Title = "\uf0c6 Document(s)", IsVisible = false };

            NavigationPage.SetHasNavigationBar(hostDashboardView.CurrentPage, false);
            NavigationPage.SetHasNavigationBar(hostMapView.CurrentPage, false);
            NavigationPage.SetHasNavigationBar(hostDocumentsView.CurrentPage, false);

            this.Children.Add(hostDashboardView);
            this.Children.Add(hostMapView);
            this.Children.Add(hostDocumentsView);

            Locator.CurrentMutable.RegisterConstant(homeDashboardView, typeof(IScreen));

Expected behavior you should navigate to the next page, but the tabs persist. This works, except for the fact that each navigation takes longer and longer, until the point where the app will no longer respond. Pages/VM are never GC'ed.

Environment(please complete the following information):

• OS: Windows
• Version 9.2.1
• Device: Xamarin.UWP

[RLittlesII]

@lackrin Thank you for reporting this issue. I see that you provided some sample code. Do you have capacity to provide a full sample? This helps verifying the fix when the issue is resolved.

I also noticed you explicitly stated that it is a Xamarin.UWP issue, are you seeing this in any other Xamarin targets?

[lackrin]

I can try to make a sample app to get the same results. I actually haven't tested with anything else because UWP is our primary platform

Do you have any examples of tab navigation where the tab remains the parent and only the tab content navigates?

On Mar 25, 2019 11:50 AM, Rodney Littles II notifications@github.com wrote:

@lackrinhttps://github.com/lackrin Thank you for reporting this issue. I see that you provided some sample code. Do you have capacity to provide a full sample? This helps verifying the fix when the issue is resolved.

I also noticed you explicitly stated that it is a Xamarin.UWP issue, are you seeing this in any other Xamarin targets?

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHubhttps://github.com/reactiveui/ReactiveUI/issues/1983#issuecomment-476308866, or mute the threadhttps://github.com/notifications/unsubscribe-auth/ATXZ8ZaKpny9YtgupbvWo9v3XzXnROygks5vaQxsgaJpZM4cHeto.

[lackrin]

https://dev.azure.com/LackrinProjects/_git/ReactiveUITabNavigation Sample APP. Problem is that it works and does not replicate the issue. I have noticed though that the View and ViewModels for the subpage are not being disposed of. I suspect this is the root of my issue, can you please verify?

Files

[RLittlesII]

I will pull this down this evening and see if I can make sense of it. Thank you for taking the time to create the sample. Appreciated.

[lackrin]

Sorry, found issue with slowdown, it was of my own doing. Had an event being added recursively

[lackrin]

Still the Model not disposing is an issue still.