C语言通信编程代码

long98194

我看到询问VB6通讯的问题，我一直使用VB6与其它RS232及RS485设备通讯。已在多个工程中应用，多口，多中断均正常，不过最今也遇到一个怪现象，有一个通讯口只要连上一跟线（RS485为两根线）执行程序便出现“内存使用超出范围”，而且与外界环境有关，等到其他部门下班，车间里的机器都停下便可以正常，应该是外部干扰造成的乱码电脑无法处理。我想你的程序也应该与此类似，不过如果你想用WINAPI编程我可以给你一个我以前用VC5编写的DLL 通讯程序的源代码。 请你参考在VB6中重写，主要用“WriteFile” 和"ReadFile"来处理.
源代码如下：
BOOL APIENTRY InitCommPort( HWND hWindows )
{
static char FAR CommDefiStr1[]="COM2";
//static char FAR CommDefiStr2[]="COM2:2400,n,8,1";
static char FAR CommDefiStr2[]="COM2: baud=2400 parity=N data=8 stop=1";
BOOL bSuccess,bid;
static DCB FAR dcb;

BuildCommDCB(CommDefiStr2,&dcb);

hCom=CreateFile("COM1",
GENERIC_WRITE|GENERIC_READ,
0,//FILE_SHARE_READ|FILE_SHARE_WRITE,
NULL,
// CREATE_ALWAYS ,
OPEN_EXISTING ,
0,//FILE_ATTRIBUTE_NORMAL ,// FILE_FLAG_OVERLAPPED ,
NULL);
bSuccess=GetCommState(hCom,&dcb);
dcb.BaudRate=9600;
dcb.ByteSize=8;
dcb.Parity=NOPARITY;
dcb.StopBits=ONESTOPBIT;
bSuccess=SetCommState(hCom,&dcb);

return 1;
}
/*BOOL APIENTRY InitCommPort( HWND hWindows )
{
static char FAR CommDefiStr1[]="COM2";
//static char FAR CommDefiStr2[]="COM2:2400,n,8,1";
static char FAR CommDefiStr2[]="COM2: baud=2400 parity=N data=8 stop=1";
BOOL bSuccess,bid;
static DCB FAR dcb;

BuildCommDCB(CommDefiStr2,&dcb);

hCom=CreateFile("c:\\fxc\\3\\newfile",//"COM2",
GENERIC_WRITE|GENERIC_READ,
FILE_SHARE_READ|FILE_SHARE_WRITE,//0,
NULL,
// CREATE_ALWAYS ,
OPEN_EXISTING ,
FILE_ATTRIBUTE_NORMAL ,// FILE_FLAG_OVERLAPPED ,
NULL);
bSuccess=GetCommState(hCom,&dcb);
dcb.BaudRate=2400;
dcb.ByteSize=8;
dcb.Parity=NOPARITY;
dcb.StopBits=ONESTOPBIT;
bSuccess=SetCommState(hCom,&dcb);
// bid=SetCommState(hhFile,&dcb);
//LPCVOID lpbuffer1="sdfgghjjkjkkl";
//LPOVERLAPPED lpOverlapped;
//LPDWORD lpp;
// address of actual bytes count
// wait flag
//WriteFile( hhFile,lpbuffer1,0x8L,lpp,lpOverlapped );
// return 0;
// if(!GetCommState(hFile,&dcb))
// if(SetCommState(hFile,&dcb))
// return 1;
//EnableCommNotification(idComDev,HWindows,4096,4096);*/
// return 1;
//else return 0;
//}*/
BOOL APIENTRY ReadCommandFromBuf1( unsigned char *aps ,DWORD count)
{
DWORD lpcount;
BOOL bResult;
COMMTIMEOUTS LPCOMMTIMEOUTS;
GetCommTimeouts(hCom,&LPCOMMTIMEOUTS);
LPCOMMTIMEOUTS.ReadIntervalTimeout= MAXDWORD;
LPCOMMTIMEOUTS.ReadTotalTimeoutMultiplier=0;
LPCOMMTIMEOUTS.ReadTotalTimeoutConstant=0;
SetCommTimeouts(hCom,&LPCOMMTIMEOUTS);
bResult = ReadFile(hCom, aps, 1, &lpcount, NULL) ;
// Check for end of file. if (bResult && nBytesRead == 0, ) {
// weˇre at the end of the file }
return bResult;
}
BOOL APIENTRY WriteByteToComm(unsigned char Schar )
{
DWORD lpcount;
BOOL bResult;
DWORD idd;
LPOVERLAPPED lpOverlapped;
char lpbuff1[]="sddfgfgfRTRT";
bResult=WriteFile(hCom,&Schar,1,&lpcount,NULL);
idd=GetLastError();
return bResult;
}

lhzjl

看不明白!还在学习中