CreateWindowEx results in System.ExecutionEngineException

[Slion]

Is it not possible to use CreateWindowEx in WinUI?

It seems that simply creating a native window will eventually results in the following exception at some point:
An unhandled exception of type 'System.ExecutionEngineException' occurred in Microsoft.WinUI.dll

[castorix]

You probably forgot something.
I often used it either for top windows or child windows
(for example, for a top window : CreateWindowEx sample)

[Slion]

You probably forgot something. I often used it either for top windows or child windows (for example, for a top window : CreateWindowEx sample)

Thanks though my case is a bit specific. I'm not actually showing the window. Just using it to process some system events. Actually just replacing a Microsoft.UI.Xaml.Window proc like below also gets me the same exception sooner or later.

iWndProcPtr = PInvoke.SetWindowLongPtr(Handle, WINDOW_LONG_PTR_INDEX.GWL_WNDPROC, Marshal.GetFunctionPointerForDelegate(iHookWndProc));

I process the messages fine at first but at some point that exception happens.

[Slion]

Ok I think I found my issue. I was allocating my wndproc in a local variable. When that gets garbage collected it crashes.
I just need to make sure I keep a reference to that WNDPROC object.
new WNDPROC(HookWndProc)

[castorix]

Ok I think I found my issue. I was allocating my wndproc in a local variable. When that gets garbage collected it crashes. I just need to make sure I keep a reference to that WNDPROC object. new WNDPROC(HookWndProc)

Yes, it is like this issue #10086
(or SetWindowSubclass instead)