Author: Tomas Rutkauskas
Is there a way to stop an application from painting during heavy calculations?
Call LockWindowUpdate() on your MainForm. Your form will not be redrawn and cannot
be moved until you unlock it by passing 0 as the window handle.
Note that LockWindowUpdate() does not hide the form nor does it reset the
WS_VISIBLE style bit.
1 2 LockWindowUpdate(MainForm.Handle); // pass the handle of window to lock3 4 // heavy calculation here5 6 LockWindowUpdate(0); // unlock it