利用Visual c++.net 编写的 时间操作演示 程序。代码都有注释。对初学者很有帮助。能实现：获取和设置的当前的系统时间；计算时间差等。-Using Visual c . Net time to prepare procedures for operation and demonstration. Code have the Notes. Very helpful for beginners. To achieve: to get and set the current syste