MFC线程实现方法及其面向对象封装，总共实现了4种封装，各有异同，非常值得学习！全部测试完毕，接口简单可以直接使用！-MFC thread implementation method and its object-oriented package, to achieve a total of four types of packaging, have similarities and differences, is worth learning! All testing is completed, the interface is simple and can be used directly!