您可以使用CreateFile()和ReadFile()等通用文件I/O API调用来完成此操作。GetCommState()和SetCommState()等附加调用可用于在串行端口打开后更改其各种设置。

HANDLE hSerial;
hSerial = CreateFile(
    "COM1",
    GENERIC_READ | GENERIC_WRITE,
    0,
    0,
    OPEN_EXISTING,
    FILE_ATTRIBUTE_NORMAL,
    0);
if(hSerial==INVALID_HANDLE_VALUE)
{
    if(GetLastError()==ERROR_FILE_NOT_FOUND)
    {
        //serial port does not exist. Inform user.
    }
    //some other error occurred. Inform user.
}

DCB dcbSerialParams = {0};
dcbSerial.DCBlength=sizeof(dcbSerialParams);
if (!GetCommState(hSerial, &dcbSerialParams))
{
    //error getting state
}
dcbSerialParams.BaudRate=CBR_19200;
dcbSerialParams.ByteSize=8;
dcbSerialParams.StopBits=ONESTOPBIT;
dcbSerialParams.Parity=NOPARITY;
if(!SetCommState(hSerial, &dcbSerialParams))
{
    //error setting serial port state
}

如果你用谷歌搜索的话，网上有很多示例代码。这里有一个例子：http://web.archive.org/web/20220426073821/http://members.ee.net/brey/Serial.pdf