为什么SIO_RCVALL要这样设置:
private const int IOC_VENDOR = 0x18000000;
private const int IOC_IN = -2147483648 /*0x80000000*/
private const int SIO_RCVALL = IOC_IN | IOC_VENDOR | 1;
private const int IOC_VENDOR = 0x18000000;
private const int IOC_IN = -2147483648 /*0x80000000*/
private const int SIO_RCVALL = IOC_IN | IOC_VENDOR | 1;