获取系统串口号,包括查询注册表、使用 EnumPort 方法、依次打开串口的方法、使用 SetupAPI 函数集的方法等4种方法，并附有实例。-Get the serial number of the system, including query the registry, use EnumPort methods in order to open the serial approach, using methods such as SetupAPI function sets the four methods, with examples.