2024年4月3日发(作者：)

1 Windows API通信函数方法

与通信有关的Windows API函数共有26个，但主要有关的有：

CreateFile() 用 “comn”（n为串口号）作为文件名就可以打开串口。

ReadFile() 读串口。

WriteFile() 写串口。

CloseHandle() 关闭串口句柄。

初始化时应注意CreateFile()函数中串口共享方式应设为0，串口为不可共享设备，其它与一般文件读

写类似。以下给出API实现的源代码。

1.1 发送的例程

//声明全局变量

HANDLE m_hIDComDev；

OVERLAPPED m_OverlappedRead, m_Over lappedWrite;

//初始化串口

void CSerialAPIView::OnInitialUpdate()

{

CView::OnInitialUpdate();

Char szComParams[50];

DCB dcb;

Memset(&m_OverlappedRead, 0, sizeof (OVERLAPPED));

Memset(&m_OverlappedWrite, 0, sizeof (OVERLAPPED));

m_hIDComDev = NULL;

m_hIDComDev = CreateFile(“COM2”, GENERIC_READ│GENERIC_WRITE, 0, NULL,

OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL│FILE_FLAG_OVERLAPPED, NULL);

if (m_hIDComDev == NULL)

{

AfxMessageBox(“Can not open serial port!”);

goto endd;

}

memset(&m_OverlappedRead, 0, sizeof (OVERLAPPED));

memset(&m_OverlappedWrite, 0, sizeof (OVERLAPPED));

COMMTIMEOUTS CommTimeOuts;

tervalTimeout=0×FFFFFFFF;

talTimeoutMultiplier = 0;

talTimeoutConstant = 0;

otalTimeoutMultiplier = 0;

otalTimeoutConstant = 5000;

SetCommTimeouts(m_hIDComDev, &CommTimeOuts);

Wsprintf(szComparams, “COM2:9600, n, 8, 1”);

m_OverlappedRead. hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

m_OverlappedWrite. hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

dcb. DCBlength = sizeof(DCB);

GetCommState(m_hIDComDev, &dcb);

dcb. BaudRate = 9600;

dcb. ByteSize= 8;

unsigned char ucSet;

ucSet = (unsigned char) ((FC_RTSCTS&FC_DTRDSR) != 0);

ucSet = (unsigned char) ((FC_RTSCTS&FC_RTSCTS) ! = 0);

ucSet = (unsigned char) ((FC_RTSCTS&FC_XONXOFF) ! = 0);