CodeAnalyzer suggestion: Application subclasses must provide activation constructor

[jonpryor]

Android application type

Classic Xamarin.Android (MonoAndroid12.0, etc.), .NET Android (net7.0-android, etc.)

Affected platform version

All

Description

When subclassing Android.App.Application, the "Activation Constructor" (IntPtr handle, JniHandleOwnership transfer) must also be provided. Failure to do so will result in runtime errors:

#8399

Steps to Reproduce

1. dotnet new android

2. Add an Application subclass

   [Application]
   public class MyApp : Application {
   }

3. run

This will crash, with adb logcat containing:

F mono-rt : [ERROR] FATAL UNHANDLED EXCEPTION: System.NotSupportedException: Unable to activate instance of type MyApp from native handle 0x7ff1f3b468 (key_handle 0x466b26f).

See also the Java Activation documentation:

There are two scenarios in which the (IntPtr, JniHandleOwnership) constructor must be manually provided on a Managed Callable Wrapper subclass:

1. Android.App.Application is subclassed. Application is special; the default Application constructor will never be invoked, and the (IntPtr, JniHandleOwnership) constructor must instead be provided.

Did you find any workaround?

No response

Relevant log output

No response