I see Sergey beat me to it, you link in to the Resize event of _screen.

In VFP 8 you can use BINDEVENT() to bind directly to that event.

The trick where you write a _screen.resize method in your class relies on the internal implementation of searching for method code for an object. That might break in future versions.
As far as I know it's not broken in VFP 8, but there's always the possibility.