using mfc controlled by a timer. Demonstrate the use of device contexts, pens, and brushes

使用MFC做的一个倒计时程序，检测现在离五点半还有多久。主要使用了ctime获取时间，使用定时器刷新窗口显示。-Use MFC to do a countdown procedures, testing now how long from half past five. The main use of the ctime acquisition time, using a timer to refresh the window.

MFC，多线程画矩形和定时器实现画矩形，多线程实现时还可以操作其他菜单而不受影响，定时器实现主界面在画图时就无法响应-MFC, multi-threaded timer, draw a rectangle and draw a rectangle, multithreading can have affected the operation of other menus, timer, the main interface will not respond when drawing

实现基于MFC的picture控件绘制曲线，使用定时器刷新-Picture control based on the MFC drawing curve, using the timer refresh