Introduction - If you have any usage issues, please Google them yourself
CDC on how to output text, graphics with a hold function, the use of collection classes CPtrArray, CPaintDC and CClientDC and application of the distinction, OnPaint and OnDraw in the relationship and achieve CView inside, rolling window implementation, coordinate space mapping, device coordinates and logical coordinates conversion. Metafile device context to use, how to use the compatible DC to achieve the preservation and reproduction of graphics.