GLWpfControl.Loaded event doesn't seem to be called, unless an additional delegate is added

[chadvandy]

Having a strange behavior where the GLWpfControl.OnLoaded() method, which just invalidates the visual of the control once it's loaded to be properly drawn, isn't run automatically, unless I specifically assign a new delegate to GLWpfControl.Loaded.

public DrawingDemo()
{
	Debug.WriteLine("Creating the DemoControl!");
	InitializeComponent();

	DemoControl.Loaded += ControlLoaded;
	Loaded += OnLoad;
	Unloaded += OnUnload;
}

private void ControlLoaded(object sender, RoutedEventArgs e)
{
	Debug.WriteLine("DemoControl loaded by OpenGL!");
}

If I comment out DemoControl.Loaded += ControlLoaded:

• The OpenGL Content remains grey until I manually resize the window.

If I keep it in:

• Automatically renders the drawn content, since InvalidateVisual() is called very early.

I'm using the LearnOpenTK tutorial right now, and I do understand there are some differences between the base assumption implementation (having the GameWindow and such) versus how it works in GLWpfControl, so I'm sure I may be misunderstanding something.
 
Using OpenTK 4.8.2, GLWpfControl 4.2.3, .NET Core 8.0.4, Visual Studio 2022 17.9.6.

Thanks for your help, and thanks for this project!

[NogginBops]

Are you calling Start() anywhere? For the GLWpfControl to work you need to call Start.

[NogginBops]

Did a little bit of testing and couldn't easily find a way to reproduce this. Will move it to 4.3.1 if this turns out to be a bug we need to fix.

[NogginBops]

Moving this to the next version. If there are no updates on this issue I'll likely close it next version.