In recent study CRectTracker in CScrollView problem of using a occur not know what is going on in the principle, problem description is as follows:

Call in ontouch dc. LPtoDP (), then logic coordinate transfer device coordinate is accurate, but when I answered the WM_PAINT message, OnPaint invokes the dc. LPtoDP (), the logical coordinates turn device coordinates is not accurate, is this why?

CodePudding user response:

Could it be the parent or the coordinates of the main window coordinates?