急：读写串口的问题

Question

为什么这么多人要串口？？ HANDLE    hCom,hCom2;DCB       dcb,dcb2;char  data[1024],recv_data[1024];
DWORD   len,send_len,error_code;
    hCom = CreateFile("com2",
              GENERIC_READ | GENERIC_WRITE,
  0,
  NULL,
                      OPEN_EXISTING,
  0,
                      //FILE_FLAG_OVERLAPPED,
  NULL);
     printf("comm2 handl is %d \n",hCom);
   
   pbuf = data;
   len = 1;
   GetCommState(hCom, &dcb ) ; 
   dcb.BaudRate =9600; 
   dcb.ByteSize =8;
   dcb.Parity = EVENPARITY
   dcb.fBinary = TRUE ;
   dcb.fParity = TRUE;
   SetCommState(hCom, &dcb ) ; //串口参数配置
   strcpy(data,"123456789");
   WriteFile(hCom,data,strlen(data),&len,0);
。   ReadFile(hCom,data,1,&len,0);//第三个参数你自己可能任一设置