NativeWindow.DestroyHandle Method ()
Destroys the window and its handle.
Assembly: System.Windows.Forms (in System.Windows.Forms.dll)
This method destroys the window associated with the Handle, sets the Handle property to 0, and calls the OnHandleChange method to reflect the change. Typically, you only call when you are done with the native window.
The NativeWindow class automatically will destroy the associated window and release its resources in response to a WM_DESTROY message.
Available since 1.1