I have to port an app written originaly in C++. One part of the app is a
custom control which handles paint and also needs input from the keyboard.
This custom control is placed in a Dialog with a WS_POPUP style. How does
one do this in C#? Further, while the custom control is handeling input,
we have to display a message box at times. In the C# version of the app,
I have set up a Form with my custom control, like this:

MyForm = new Form();
MyForm.Controls.Add( new MyCustomControl());
MyForm.SetActiveControl( ...);

Furthur processing is done in the custom control, which handles keyboard
input. However, if I display a messagebox, then the focus goes God-alone-knows