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#include <windows.h>
#include <cstdio>
#include <iomanip>
#include <iostream>
#include <string>
#include <vector>

const char* StopBitsFromInt(int s) {
    switch (s) {
    case ONESTOPBIT:
        return "1 stop bits";
    case ONE5STOPBITS:
        return "5 stop bits";
    case TWOSTOPBITS:
        return "2 stop bits";
    }
    return "Unknown stop bits";
}

const char* ParityFromInt(int s) {
    switch (s) {
    case NOPARITY:
        return "no-parity";
    }
    return "other parity";
}

HANDLE MustOpenCommport() {
    HANDLE hComm = CreateFile(L"\\\\.\\COM4",                //port name
        GENERIC_READ | GENERIC_WRITE, //Read/Write
        0,                            // No Sharing
        NULL,                         // No Security
        OPEN_EXISTING,// Open existing port only
        0,            // Non Overlapped I/O
        NULL);        // Null for Comm Devices

    if (hComm == INVALID_HANDLE_VALUE) {
        std::cerr << "Error in opening serial port" << std::endl;
        ExitProcess(-1);
    } else {
        //std::cout << "opening serial port successful" << std::endl;
    }
    //CloseHandle(hComm);//Closing the Serial Port
    return hComm;
}

void ShowCommStatus(HANDLE hComm) {
    DCB dcbParams = { sizeof(DCB) };
    BOOL status = GetCommState(hComm, &dcbParams);
    std::cout << "Baudrate:" << dcbParams.BaudRate << std::endl;
    std::cout << "Parity:" << ParityFromInt(dcbParams.fParity) << std::endl;
    std::cout << "ByteSize:" << int(dcbParams.ByteSize) << std::endl;
    std::cout << "StopBit:" << StopBitsFromInt(dcbParams.StopBits) << std::endl;
}

int main() {
    HANDLE hComm = MustOpenCommport();
    DCB dcbParams = { sizeof(DCB) };

    //std::cout << "setting ...\n\n" << std::endl;
    dcbParams.BaudRate = CBR_128000;// CBR_256000;// CBR_9600;
    dcbParams.ByteSize = 8;
    dcbParams.StopBits = ONESTOPBIT; // 1
    dcbParams.Parity = NOPARITY;

    BOOL setOK = SetCommState(hComm, &dcbParams);
    if (!setOK) {
        std::cerr << "error setting comm-state" << std::endl;
        ExitProcess(-1);
    }

    //ShowCommStatus(hComm);

    if (!SetCommMask(hComm, EV_RXCHAR)) {
        std::cerr << "error_category set-comm mask" << std::endl;
        ExitProcess(-1);
    }

    while (1) {
        DWORD dwEventMask = 0;
        DWORD status = WaitCommEvent(hComm, &dwEventMask, NULL);
        if (!(dwEventMask&EV_RXCHAR)) {
            std::cout << "Unknown event" << std::endl;
            continue;
        }
        std::cout << "-->>" << std::endl;
        DWORD bytesRead = 0;
        //std::string buffer;
        char tempChar;
        do {
            if (!ReadFile(hComm, &tempChar, sizeof(tempChar), &bytesRead, NULL)) {
                std::cerr << "read failed" << std::endl;
                break;
            }
            if (bytesRead > 0) {
                //buffer += tempChar;
                std::cout << tempChar;
            } else {
                break;
            }
            //std::cout << buffer;
        } while (1);
    }
    CloseHandle(hComm);
}

参考链接:


http://xanthium.in/Serial-Port-Programming-using-Win32-API

这里有一个问题就是 一旦进入ReadFile的那个while循环， 只要不是让设备关闭（如掉电）， ReadFile就不会失败。

总贴：


https://msdn.microsoft.com/en-us/library/ff802693.aspx