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Suppress form repaints during calculations

Question: Is there a way to stop an application from painting during heavy calculations? Answer: 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. Also note that the final call of LockWindowUpdate(0) - which is required to unlock updates - will cause a lot of flicker as it repaints all application's visible windows/ controls. Use this function with care only when absolutely necessary. LockWindowUpdate(MainForm.Handle); // pass the handle of window to lock // heavy calculation here LockWindowUpdate(0); // unlock it