同步读串口，ReadFile 返回TRUE，读取的字节数却是0 ----- 解决办法是设置超时值

设置超时值

SetCommTimeouts(HANDLE hCom, LPCOMMTIMEOUTS lpTimeouts )


HANDLE hComm = CreateFile(...)

//After CreateFile and before ReadFile
//Set Timeout value.
COMMTIMEOUTS timeout;
Port.GetTimeouts(timeout);
timeout.ReadIntervalTimeout =
MAXDWORD;
timeout.ReadTotalTimeoutConstant = 1000;
//ms. the total timeout = Multiplier * nBytesToRead + constant
timeout.ReadTotalTimeoutMultiplier = 1000;
// ms
SetCommTimeouts(hComm, &timeouts)

ReadFile(...)