在Visual C++中写入串行(Com)端口

Question

我有一个连接在端口COM4上的设备(115200波特,8-N-1).根据我在这里找到的例子,我打开端口:

                    Keyboard_Handle=CreateFile("\\\\.\\COM4",GENERIC_WRITE,0,NULL,OPEN_EXISTING,FILE_FLAG_OVERLAPPED,NULL); 
                    if(GetLastError() !=0 || Keyboard_Handle == INVALID_HANDLE_VALUE)
                    {
                        AfxMessageBox("Error opening connection to Keyboard");
                        exit(1);
                    }


                    char buffer[100];
     strcpy(buffer,"baud=115200 parity=N data=8 stop=1");
     BuildCommDCB((char*)&buffer,&dcb)) 

     if(GetCommState(Keyboard_Handle, &dcb))
     {
      dcb.BaudRate = CBR_115200;
      dcb.ByteSize = 8;
      dcb.Parity = 0;
      dcb.StopBits = 1;
      SetCommState(Keyboard_Handle, &dcb);
     } 

稍后在我的代码中,我在端口上调用WriteFile:

    LPDWORD bytes_written;
    LPDWORD bytes_read;
    LPOVERLAPPED OVERLAP;
    char write_buf[10];

    write_buf[0] = 's';
    write_buf[1] = '\0';

    if(Keyboard_Handle != NULL) {
    WriteFile(Keyboard_Handle, (LPCVOID)write_buf , strlen(write_buf), bytes_written, OVERLAP); 
    }

每次我运行代码时,我都会得到JIT调试器抱怨未处理的异常(尽管WriteFile在Try/catch块中).

我是怎么做的？

Answer 1

bytes_written需要是变量的地址; 编译器不会编译您发布的语句.

同样," OVERLAP"没有意义.

你检查一下是否CreateFile成功了？

什么write_buf时候你打电话strlen给它？

尝试复制并粘贴您正在使用的实际代码.

此外,这似乎不是您正在使用的非常好/信息丰富的样本.尝试Windows串口编程和http://msdn.microsoft.com/en-us/library/ms810467.aspx

还可以从Microsoft站点的示例程序开始,在修改它之前对其进行测试(以检查它是否在您的计算机上运行),然后进行修改.