Release build of sample app fails when startup page replaced with simple NavigationPage (Android)

[hbraasch]

Description

When generating a new MAUI app from scratch, the Android [Release] build version fails to run. This happens if the startup page is changed from:
MainPage = new AppShell();
to:
MainPage = new NavigationPage(new StartupPage()) { BarBackgroundColor = Colors.Grey, BarTextColor = Colors.White};
The [StartupPage.cs] is extremely basic and should not be the problem.
When building as [Debug] both the unmodied and modified apps works fine.
When building as [Release], the unmodified app works fine, the modified one fails.
A reproduction project is supplied:
https://github.com/hbraasch/PublishTester.git

All works fine under iOS.

Steps to Reproduce

1. Load the reproduction app into VS.

2. Ensure inside [App.xaml.cs], the modification is commented out:
   

3. Create a release build and run the app. Observe it runs fine.

4. Ensure the modification is uncommented:

5. Create a debug build and run the app. Observe it runs fine.
6. Create a release build and run the app. Observe it starts to load, shows a purple splash screen, then abruptly closes.

Version with bug

Release Candidate 3 (current)

Last version that worked well

Unknown/Other

Affected platforms

Android

Affected platform versions

Android 12 - API 31, Android 11 = API 30

Did you find any workaround?

None

Relevant log output

No response

[pijnappel]

Can confirm, happens in my app too. I added some error handling. Here is the stack trace of my app:

Microsoft.Maui.Platform.ToPlatformException: Microsoft.Maui.Handlers.NavigationViewHandler found for Microsoft.Maui.Controls.NavigationPage is incompatible
 ---> System.InvalidProgramException: Invalid IL code in Microsoft.Maui.Handlers.NavigationViewHandler:CreatePlatformView (): IL_002a: ldnull    


   at Microsoft.Maui.Handlers.ViewHandler`2[[Microsoft.Maui.IStackNavigationView, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Android.Views.View, Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065]].OnCreatePlatformView()
   at Microsoft.Maui.Handlers.ViewHandler.OnCreatePlatformElement()
   at Microsoft.Maui.Handlers.ElementHandler.CreatePlatformElement()
   at Microsoft.Maui.Handlers.ElementHandler.SetVirtualView(IElement view)
   at Microsoft.Maui.Handlers.ViewHandler.SetVirtualView(IElement element)
   at Microsoft.Maui.Handlers.ViewHandler`2[[Microsoft.Maui.IStackNavigationView, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Android.Views.View, Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065]].SetVirtualView(IView view)
   at Microsoft.Maui.Handlers.ViewHandler`2[[Microsoft.Maui.IStackNavigationView, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Android.Views.View, Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065]].SetVirtualView(IElement view)
   at Microsoft.Maui.Controls.Element.SetHandler(IElementHandler newHandler)
   at Microsoft.Maui.Controls.Element.set_Handler(IElementHandler value)
   at Microsoft.Maui.Controls.VisualElement.Microsoft.Maui.IElement.set_Handler(IElementHandler value)
   at Microsoft.Maui.Platform.ElementExtensions.ToHandler(IElement view, IMauiContext context)
   Exception_EndOfInnerExceptionStack
   at Microsoft.Maui.Platform.ElementExtensions.ToHandler(IElement view, IMauiContext context)
   at Microsoft.Maui.Platform.ElementExtensions.ToPlatform(IElement view, IMauiContext context)
   at Microsoft.Maui.Platform.ContainerView.SetView(IElement view, Boolean forceRefresh)
   at Microsoft.Maui.Platform.ContainerView.set_CurrentView(IElement value)
   at Microsoft.Maui.Platform.ElementExtensions.ToContainerView(IElement view, IMauiContext context)
   at Microsoft.Maui.Platform.NavigationRootManager.Connect(IView view, IMauiContext mauiContext)
   at Microsoft.Maui.Handlers.WindowHandler.MapContent(IWindowHandler handler, IWindow window)
   at Microsoft.Maui.PropertyMapper`2.<>c__DisplayClass5_0[[Microsoft.Maui.IWindow, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Microsoft.Maui.Handlers.IWindowHandler, Microsoft.Maui, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].<Add>b__0(IElementHandler h, IElement v)
   at Microsoft.Maui.PropertyMapper.UpdatePropertyCore(String key, IElementHandler viewHandler, IElement virtualView)
   at Microsoft.Maui.PropertyMapper.UpdateProperty(IElementHandler viewHandler, IElement virtualView, String property)
   at Microsoft.Maui.Handlers.ElementHandler.UpdateValue(String property)
   at Microsoft.Maui.Controls.Window.OnPropertyChanged(String propertyName)
   at Microsoft.Maui.Controls.BindableObject.SetValueActual(BindableProperty property, BindablePropertyContext context, Object value, Boolean currentlyApplying, SetValueFlags attributes, Boolean silent)
   at Microsoft.Maui.Controls.BindableObject.SetValueCore(BindableProperty property, Object value, SetValueFlags attributes, SetValuePrivateFlags privateAttributes)
   at Microsoft.Maui.Controls.BindableObject.SetValue(BindableProperty property, Object value, Boolean fromStyle, Boolean checkAccess)
   at Microsoft.Maui.Controls.BindableObject.SetValue(BindableProperty property, Object value)
   at Microsoft.Maui.Controls.Window.set_Page(Page value)
   at Microsoft.Maui.Controls.Application.set_MainPage(Page value)

[hbraasch]

Great, thanks for checking.

[kristinx0211]

verified repro on android 11 using the above project with vs 17.3.0 Preview 2.0 [32515.5.main].

[sgellock]

@kristinx0211 is there a workaround while waiting on an update?

[Michal-MK]

GA makes past the splash screen, but when I try to call PopAsync() it does not do anything... I have not checked logcat output yet due to time constratints... but maybe it has something to say.

[hbraasch]

I just installed the latest release of Visual Studio [17.3.0 Preview 1.1] this morning, and it appears the issue demonstrated in my repro project [https://github.com/hbraasch/PublishTester.git] has been resolved!
The app now runs under [Release] build. I also checked it by running a more real-world app under[Release], and it also now runs successfully.
In my opinion, my issue has been resolved. Well done and thanks!
There are other developers also interested in this issue, so I suggest we leave this issue open until they have reported on ther experience. If only up to me, I would close this issue.

[Michal-MK]

Alright after an unholy amount of time spent trying to find the root cause I have found it along with a workaround... so here it goes.

Lets have a ContentPage

<?xml version="1.0" encoding="utf-8" ?>
<base:ContentPageBase xmlns:base="clr-namespace:ERecept.MAUI.Views.Base"
                      xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
                      xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
                      xmlns:vm="clr-namespace:ERecept.Core.ViewModel;assembly=ERecept.Core"
                      xmlns:uc="clr-namespace:ERecept.MAUI.Views.UserControls"
                      x:Class="ERecept.MAUI.Views.Pages.UserInfoPage"
                      x:DataType="vm:UserInfoPageVM">
    <Grid RowDefinitions="auto, *, auto">
        <uc:BackNav/>
        <uc:UserDetails Margin="8" BindingContext="{Binding UserDetails}" Grid.Row="1"/>
        <Button Grid.Row="2" Text="Log Out" Command="{Binding LogOutCommand}"
                BackgroundColor="{StaticResource DestructiveActionColor}"
                Margin="16,0,16,32"/>
    </Grid>
</base:ContentPageBase>

The base:ContentPageBase is just a wrapper that sets my BindingContext, not important. Note the x:DataType.

<uc:BackNav/>:

<ContentView xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:vm="clr-namespace:ERecept.Core.ViewModel.Base;assembly=ERecept.Core"
             x:Class="ERecept.MAUI.Views.UserControls.BackNav"
             x:DataType="vm:MedicamentDetailVM">
    <Grid ColumnDefinitions="auto, *" RowDefinitions="auto" BackgroundColor="{StaticResource PrimaryColor}" Padding="8">
        <ImageButton Source="previous.png" Command="{Binding BackCommand}" HeightRequest="40" WidthRequest="40" Aspect="AspectFit"/>
        <Label Grid.Column="1" TextColor="White" VerticalTextAlignment="Center" FontSize="20"
               Text="{Binding NavText}"
               Padding="16,0,0,0"/>
    </Grid>
</ContentView>

Again here note the x:DataType.

The two classes are different but inherit from a common class ParametrizedBaseViewModel<T> Which defines the BackCommand property.

public class ParametrizedBaseViewModel<T> : INotifyPropertyChanged {
    public ICommand BackCommand { get; set; }
}

Why is the x:DataType different?

• I assume that x:DataType is just a hint about what type my BindingContext will be so that I get IntelliSense in xaml... correct me if I am wrong. So I just put in any ViewModel I found since all contain the same property and XAML does not support generics afaik.

Now this does not work in Release Configuration, but runs fine in Debug Configuration.

When I change the x:DataType to the same type as in the parent ContentPage the navigation works in Release as well, but only for that specific ContentPage.

The workaround

Create an interface for the base class:

public interface IRedundantInterface {
	ICommand BackCommand { get; set; }
}

Make the ParametrizedBaseViewModel<T> implement IRedundantInterface and change the x:DataType in BackNav to that interface type.

Why?

The Binding to the BackCommand property does not happen in Release without the workaround. Why? The type specified contains the property of the same name. Is x:DataType doing something else than just type hints? Why do other bindings work => the NavText on Label?

[mattleibow]

Just tested with the latest version of MAUI and this no longer happens. I think this happened around the time Google changed the ABI of some of the controls and broke things:

System.InvalidProgramException: Invalid IL code in Microsoft.Maui.Handlers.NavigationViewHandler:CreatePlatformView ():IL_002a: ldnull