GetCommState(m_hComm,&commParam) //这里执行不成功,GetLastError可以看到.返回值为21.设备未就绪。
跳过去.
在读数据时
PurgeComm(ceSeries->m_hComm,PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR
| PURGE_RXCLEAR );
SetCommMask (ceSeries->m_hComm, EV_RXCHAR );
后
WaitCommEvent(ceSeries->m_hComm,&evtMask,0);//这里执行也不成功,读不到状态的变化.理所当然evtMask也不有值返回.
因此if (evtMask & EV_RXCHAR) 也没有这个状态..
但:
ClearCommError(ceSeries->m_hComm,&dwReadErrors,&cmState);
willReadLen = cmState.cbInQue ; //这里有值噢!!!
ReadFile(ceSeries->m_hComm, readBuf, willReadLen, &actualReadLen,0); //这里能读到数据噢..困惑呀....
为什么会这样呢?
GetCommState和WaitCommEvent都不能执行.
但能读到数据.........
所以现在好困惑这样的程序到底能不能用.....
有经验的兄台帮我看看程序那里有问题,十分感谢...
//打开COM4口代码
DCB commParam;
commParam.DCBlength = sizeof(DCB);
TCHAR szPort[15];
COMMTIMEOUTS CommTimeOuts;
// 已经打开的话，直接返回
if (m_hComm != INVALID_HANDLE_VALUE)
{
return TRUE;
}
m_hComm = CreateFile (L"COM4:",GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING,0, NULL); //成功
if (m_hComm == INVALID_HANDLE_VALUE)
{
// 无效句柄,返回。
TRACE(_T("CreateFile 返回无效句柄\n"));
return false;
}
//设置串口读写时间
GetCommTimeouts (m_hComm, &CommTimeOuts);
CommTimeOuts.ReadIntervalTimeout = MAXDWORD;
CommTimeOuts.ReadTotalTimeoutMultiplier = 0;
CommTimeOuts.ReadTotalTimeoutConstant = 0;
CommTimeOuts.WriteTotalTimeoutMultiplier = 10;
CommTimeOuts.WriteTotalTimeoutConstant = 1000;
if(!SetCommTimeouts( m_hComm, &CommTimeOuts ))
{
TRACE( _T("SetCommTimeouts 返回错误") );
//关闭串口
CloseHandle (m_hComm); //关闭线程
m_hComm = INVALID_HANDLE_VALUE;
return FALSE;
}
//指定端口监测的事件集
SetCommMask (m_hComm, EV_RXCHAR);
//分配设备缓冲区
SetupComm(m_hComm,512,512);
//初始化缓冲区中的信息
PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
// 得到打开串口的当前属性参数，修改后再重新设置串口。
GetCommState(m_hComm,&commParam); //执行不城功也不理,直接运行一下.
//设置串口参数
//if (!GetCommState(m_hComm,&commParam)) //这里执行不成功,GetLastError可以看到.返回值为21.设备未就绪。
//{
// //关闭串口
// UINT dw = GetLastError();
// CString errstr ;
// //errstr.Format("错误代码为:%d" ,dw);
// //wsprintf(errstr,"错误代码为:%d" ,dw);
// //TRACE(dw);
// TRACE(_T("GetCommState 出错\n"));
// CloseHandle (m_hComm); //关闭线程
// m_hComm = INVALID_HANDLE_VALUE;
// return FALSE;
//
//}
commParam.BaudRate = 9600; //波特率
commParam.fBinary = TRUE; //Win32不支持非二进制串行传输模式，必须为TRUE
commParam.fParity = TRUE; //启用奇偶校验
commParam.fOutxCtsFlow = TRUE; //串行端口的输出由CTS线控制
commParam.fOutxDsrFlow = FALSE; //关闭串行端口的DSR流控制
commParam.fDtrControl = DTR_CONTROL_ENABLE; //启用DTR线
commParam.fDsrSensitivity = FALSE; //如果设为TRUE将忽略任何输入的字节，除非DSR线被启用
//commParam.fTXContinueOnXoff = TRUE; //当为TRUE时，如果接收缓冲区已满且驱动程序已传送XOFF字符，将使驱动程序停止传输字符
commParam.fTXContinueOnXoff = FALSE;
commParam.fOutX = FALSE; //设为TRUE指定XON/XOFF控制被用于控制串行输出
commParam.fInX = FALSE; //设为TRUE指定XON/XOFF控制被用于控制串行输入
commParam.fErrorChar = FALSE; //WINCE串行驱动程序的默认执行将忽略这个字段
commParam.fNull = FALSE; //设为TRUE将使串行驱动程序忽略收到的空字节
commParam.fRtsControl = RTS_CONTROL_ENABLE; //启用RTS线
commParam.fAbortOnError = FALSE; //WINCE串行驱动程序的默认执行将忽略这个字段
commParam.ByteSize = 8; //每字节的位数
commParam.Parity = NOPARITY; //无奇偶校验
commParam.StopBits = ONESTOPBIT; //每字节一位停止位
//设置串口参数
if (!SetCommState(m_hComm, &commParam))
{
TRACE(_T("SetCommState error"));
//关闭串口
CloseHandle (m_hComm); //关闭线程
m_hComm = INVALID_HANDLE_VALUE;
return FALSE;
}
困惑的是:
//设置端口上指定信号的状态
// SETDTR: 发送DTR (data-terminal-ready)信号
// SETRTS: 发送RTS (request-to-send)信号
EscapeCommFunction (m_hComm, SETDTR);
EscapeCommFunction (m_hComm, SETRTS);
//创建串口读数据监听线程
m_hReadThread = CreateThread(NULL,0,ReadThreadFunc,this,0,&m_dwReadThreadID);
//下面是线程中的程序.
CCESeries *ceSeries = (CCESeries*)lparam; //带进来的实例,也就是ceSeries->m_hComm就是COM口句柄.
DWORD evtMask;
BYTE * readBuf = NULL;//读取的字节
DWORD actualReadLen=0;//实际读取的字节数
DWORD willReadLen;
DWORD dwReadErrors;
COMSTAT cmState;
OVERLAPPED ovread ; //Windows CE不支持Windows下常用的串行通信重叠I/O方式（OVERLAPPED）
//http://www.yctek.com/2009/0114/19.html
// 清空缓冲，并检查串口是否打开。
ASSERT(ceSeries->m_hComm !=INVALID_HANDLE_VALUE);
//清空串口
//PurgeComm(ceSeries->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR );
PurgeComm(ceSeries->m_hComm,PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR
| PURGE_RXCLEAR );
SetCommMask (ceSeries->m_hComm, EV_RXCHAR );//| EV_CTS | EV_DSR ); //设置事件掩模来监视指定通信端口上的事件
//memset( &ovread, 0x00, sizeof(OVERLAPPED) ) ;
//ovread.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL) ;
while (TRUE)
{
PurgeComm(ceSeries->m_hComm,PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR| PURGE_RXCLEAR );
SetCommMask (ceSeries->m_hComm, EV_RXCHAR );
//if (WaitCommEvent(ceSeries->m_hComm,&evtMask,&ovread)) //不知为什么这个执行不成功,所以去除了.
//if (WaitCommEvent(ceSeries->m_hComm,&evtMask,0))
//{
WaitCommEvent(ceSeries->m_hComm,&evtMask,0); //只好直接执行啦.根本就不会返回EV_RXCHAR 事件
//SetCommMask (ceSeries->m_hComm, EV_RXCHAR | EV_CTS | EV_DSR );
//表示串口收到字符
//if (evtMask & EV_RXCHAR) //根本就不会返回EV_RXCHAR 事件,所以也就只好去掉啦.....
//{
ClearCommError(ceSeries->m_hComm,&dwReadErrors,&cmState);
willReadLen = cmState.cbInQue ; //奇怪的是这里有数据噢......有数据,那就去读吧.....
if (willReadLen <= 0)
{
continue;
}
willReadLen=willReadLen>1024 ? 1024 : willReadLen;
//分配内存
readBuf = new BYTE[willReadLen];
ZeroMemory(readBuf,willReadLen); //填充内存
//读取串口数据
ReadFile(ceSeries->m_hComm, readBuf, willReadLen, &actualReadLen,0); //这里竟能读到噢..困惑呀....
//如果读取的数据大于0，
if (actualReadLen>0)
{
//触发读取回调函数
if (ceSeries->m_OnSeriesRead)
{
ceSeries->m_OnSeriesRead(ceSeries->m_pOwner,readBuf,actualReadLen);
}
}
//释放内存
delete[] readBuf;
readBuf = NULL;
//}
/*}
else
{
int oooerr= GetLastError();
DWORD dwErrors;
COMSTAT comStat;
memset(&comStat,0,sizeof(comStat));
ClearCommError(ceSeries->m_hComm,&dwErrors,&comStat);
continue;
}*/
//如果收到读线程退出信号，则退出线程
if (WaitForSingleObject(ceSeries->m_hReadCloseEvent,500) == WAIT_OBJECT_0)
{
break;
}
}
return 0;
