Declaration
procedure UpdateRect(ARect: TRect; UpdateNow: Boolean = false);
Description
Updates the specified rectangle. Use this function instead of Update when only a portion of the image has changed.
If UpdateNow is True then the window is updated immediately (bypassing the application queue).
Example
// we assume that Zoom = 100
ImageEnView1.IEBitmap.Canvas.Fill(0, 0, 10, 10);
ImageEnView1.UpdateRect(rect(0, 0, 10, 10));