Introduction - If you have any usage issues, please Google them yourself
In the Microsoft base class library MFC, the CDC class is the base class that defines the device context object, and all the drawing functions are defined in the CDC base class. When you need to output text or graphics, you need to call the CDC class member functions, these member functions with output text, drawing graphics function.
The routines explained in this section are all in the TestView.cpp file
Implementation of void CTestView:: OnDraw (CDC* pDC) function.