Getting a System.AccessViolationException when trying to use ClosedRequested event

[Eatham532]

Hey trying to use the ClosedRequested event but am getting a System.AccessViolationException. This only happens when trying to build for windows. It works when building for GTK.

System.AccessViolationException: 'Attempted to read or write protected memory. This is often an indication that other memory is corrupt.'

Followed this from the wiki: https://platform.uno/docs/articles/features/app-close-handler.html

Double checked that I added <rescap:Capability Name="confirmAppClose"/> to the package.appxmanifest

I do recal it working before. Probably when I was not using the Uno.Extensions.Navigation and instead was using frame navigation.

[jeromelaban]

Thanks for the report. This particular API is not available on WinAppSDK, and you'll need to use the AppWindow APIs instead for windows only.

[Eatham532]

I added a handler function to the closing event like this within the OnLaunched method
MainWindow.AppWindow.Closing += AppWindowOnClosing;

Using that I can cancel the window from closing. However it seems I get an exception when trying to show a MessageDialog.

System.Runtime.InteropServices.COMException: 'Invalid window handle. (0x80070578) Consider WindowNative, InitializeWithWindow See https://aka.ms/cswinrt/interop#windows-sdk'