How to create a reference to a delegate so that the garbage collector does not destroy it?

Question

C++ / C#

When resizing the application window, a delegate is called, which is passed to unmanaged code, and the program crashes with an error: A delegate of type "OPENGL_SDK!OPENGL_SDK.Glut+dReshapeFunc::Invoke" received by the garbage collector was called back. This can cause application crashes and data corruption or loss. When passing delegates to unmanaged code, a managed application must keep them alive until it is guaranteed that they will never be called again.
I can guess what needs to be done so that in managed code the delegate remains throughout the life of the program, but I do not know how to do this.

Answer 1

Keep a reference to this delegate in some global variable before passing it to unmanaged code.

Answer 2

Declare a static field.