Determine Whether Program is the Active Window in .NET

Question

I have a C#/.NET app and I want to implement the following behavior:

I have a popup menu. Whenever the user clicks on anything within the application that

Answer 1

You could P/Invoke into GetForegroundWindow(), and compare the HWND returned to the application's form.Handle property.

Once you have the handle, you can also P/Invoke GetAncestor() to get the root owner window. This should be the handle of your application's main, startup window, if this is in your application.