VC多线程编程实例，多接收模式串口类，接收模式有四种：手动查询串口方式(ManualQueryRecv)、手动定长查询方式(ManualConstRecv)、自动信号查询方式(AutoRecvBySignal)、自动中断查询方式(AutoRecvByBreak)。-VC multithreaded programming examples, multi-category serial receive mode, there are four reception modes: manual che