Introduction - If you have any usage issues, please Google them yourself
		 
1. First, the establishment of a basic dialogue exe project, and named the time  2. In the BOOL CTimeDlg:: OnInitDialog () function is the establishment of a timer, SetTimer (1,1000, NULL)  3. Then the establishment of the message to respond to classwizard function void CTimeDlg:: OnTimer (UINT nIDEvent), enter the code inside is as follows: Invalidate ()  4. then classwizard set-up message response function void CTimeDlg:: OnDestroy (), enter the code inside the following: KillTimer (1)  to this to eliminate the timer  5. void CTimeDlg:: OnPaint () where importation of the above algorithm  6. CtimeDlg class to add header file for the math.h, the code:# include " math.h" . 7. Compile, link and run.