用MFC写的一个计算器，比较简单，包含常见运算，当然有更好的写法，计算其中的 没实现，应该和=差不多，当然在我测的时候，有时候会出现BUG，整体思想是很简单。-Using MFC to write a calculator, simple, contains common operations, of course, better writing, calculation of of them did not realize, and = should be almost, of course