Question

MFC串口通信

这是我写的代码，帮忙看下为什么通信不成功？
客户端：
void CDeviceDlg::OnOK()
{
// TODO: Add extra validation here
HANDLE hCom;
hCom =CreateFile("COM4",GENERIC_WRITE|GENERIC_READ,NULL,0,OPEN_EXISTING,0,NULL);
if(hCom==INVALID_HANDLE_VALUE)
{
AfxMessageBox("无法打开串口 ! ");
}
DCB dcb;
GetCommState(hCom,&dcb);
dcb.BaudRate = CBR_115200 ; //波特率为 9600
dcb.ByteSize = 8 ; // 数据位为 8
dcb.StopBits = ONESTOPBIT ; //停止位为 1
dcb.Parity = NOPARITY ; //无校验
SetCommState(hCom, &dcb) ;
SetupComm(hCom, 1024, 1024);
COMMTIMEOUTS TimeOuts;
TimeOuts.ReadIntervalTimeout=1000;
TimeOuts.ReadTotalTimeoutMultiplier=500;
TimeOuts.ReadTotalTimeoutConstant=5000;
TimeOuts.WriteTotalTimeoutMultiplier=500;
TimeOuts.WriteTotalTimeoutConstant=2000;
SetCommTimeouts(hCom,&TimeOuts);
PurgeComm(hCom,PURGE_TXCLEAR|PURGE_RXCLEAR);
BYTE cmd_s = 'S', cmd_e = 'E', cmd_wait = 0;
DWORD dwRead = 0, dwWrite = 0;
BYTE data[10] = {1, };
WriteFile(hCom, &cmd_s, 1, &dwWrite, NULL);
do{
ReadFile(hCom, &cmd_wait, 1, &dwRead, NULL);

}while('A'!= cmd_wait);
WriteFile(hCom, data, 10, &dwWrite, NULL);
cmd_wait = 0 ;
do {
ReadFile(hCom, &cmd_wait, 1, &dwRead, NULL);
}while('A'!= cmd_wait) ;

// WriteFile(hCom, &cmd_e, 1, &dwWrite, NULL) ;

CloseHandle(hCom) ;
}
服务器：
void CHostDlg::OnOK()
{
// TODO: Add extra validation here
//前面的一样 省略了端口是COM3
BYTE cmd_s = 'S', cmd_e = 'E', cmd_wait = 0,cmd_a='A';
DWORD dwRead = 0, dwWrite = 0;
BYTE data[10] = {0, };
// WriteFile(hCom, &cmd_s, 1, &dwWrite, NULL);
do{
ReadFile(hCom, &cmd_wait, 1, &dwRead, NULL);

}while('S'!= cmd_wait);
WriteFile(hCom, &cmd_a, 1, &dwWrite, NULL);
cmd_wait = 0 ;
MessageBox("1111","1111",MB_OK); //验证
do {
ReadFile(hCom, data, 10, &dwRead, NULL);
}while('1'!= data[0]) ;

buf.Format(TEXT("%d",data[0]));
m_edit.SetWindowText(buf);

// WriteFile(hCom, &cmd_e, 1, &dwWrite, NULL) ;

CloseHandle(hCom) ;
}

Answer 1

又是COM3又是COM4，串口成员变量用全局的。另外先把发送搞定再处理接收，用串口监视软件监视发送数据。一般API是多线程通信的，打开串口以后会创建监视线程，监视缓冲区的数据，看你的好像没有。。。所以失败是正常的

Answer 2

1、代码太多，没耐心看
2、基本功能没描述，看了也白看

Answer 3

网上有SerialPort的类，封装好了，你直接用就行 ，功能别堆在一个函数里写

Answer 4

1，最好下载一个模拟串口工具和串口调试器助手试试
2，串口没有打开混叠读写，不支持双工，所以服务器和客户端要读写协调一致
3，有些串口设置完毕后，通信建立前，需要发送握手信号：
EscapeCommFunction(hCom, SETDTR)
不知道你的串口硬件是怎么设置的