免费串口通信API实例函数（C源代码）

/* ******************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <conio.h>
 
HANDLE hComm;
OVERLAPPED m_ov;
COMSTAT comstat;
 
 
ProcessErrorMessage(char* ErrorText)
{
   char *Temp = new char[200];
   LPVOID lpMsgBuf;
   FormatMessage(
   FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
   NULL,
   GetLastError(),
   MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
   (LPTSTR) &lpMsgBuf,
   0,
   NULL
   );
   sprintf(Temp, "WARNING: %s Failed with the following error: \n%s\nPort: %d\n", (char*)ErrorText, lpMsgBuf, "com2");
   MessageBox(NULL, Temp, "Application Error", MB_ICONSTOP);
   LocalFree(lpMsgBuf);
   delete[] Temp;
 return true;
}

 
bool openport(char *portname)//打开一个串口
{
 
hComm = CreateFile(portname,
                  GENERIC_READ | GENERIC_WRITE,
                  0,
                  0,
                  OPEN_EXISTING,
                  FILE_FLAG_OVERLAPPED,
                  0);
if (hComm == INVALID_HANDLE_VALUE)
return FALSE;
else
return true;
}
 
bool setupdcb(int rate_arg)
{
 DCB dcb;
 int rate= rate_arg;
 memset(&dcb,0,sizeof(dcb));
 if(!GetCommState(hComm,&dcb))//获取当前DCB配置
 {
 ProcessErrorMessage("GetCommState()");
 return FALSE;
 }
 /* -------------------------------------------------------------------- */
 // set DCB to configure the serial port
       dcb.DCBlength      = sizeof(dcb);