说明：  vc里好多得地方容易让人混淆，比如，一些宏和变量只是大小写得区别，很容易让人迷惑得，该文章里介绍了不少类似得容易混淆得地方
(vc good are many the place to be easy to let the person confuse, for instance, some great and the variable only is the big small letter results in the difference, is very easy to let the person confuse, in this article introduced many is similar easily to confuse results in the place )