在线求助，com口的问题（来者有分）(100分)

我用 api 函数写了个com 口的读函数，<br>出现如下问题：<br>如果电脑刚刚启动后启动程序， <br> &nbsp; &nbsp;Readsuccess := ReadFile(m_hComm, &nbsp; &nbsp; &nbsp; &nbsp; //操作句柄<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;bStr[0], &nbsp; &nbsp; &nbsp; &nbsp;//数据缓冲区<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;NumberOfBytesToRead, &nbsp; //要读取的字节长度<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;iReadNum, &nbsp; &nbsp; &nbsp; &nbsp;//实际读取的字节长度<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;nil); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //overlapped buffer<br> &nbsp;则上述 api 函数长时间不返回，程序无响应。<br>如果我先用串口 调试工具打开某串口然后再关闭， 然后用我的程序调试，就能一直保持正常运行（不论我的程序开闭多少次，只要不重起电脑，就能正常运行）。<br>请各位朋友帮忙指点，或者指出我可能的错误。<br>来者有分

你要com有个初化呀

com 初始化已有，如下，不知是不是不全面或者其他的，用串口调试打开一次之后就能用了～！ <br>constructor TSerialControl.Create; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//TSerialControl类对象构造方法实现区<br>begin<br> &nbsp; &nbsp;inherited Create; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //执行父类的Create方法<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//以下为变量初始化<br> &nbsp; &nbsp;m_hComm := DWord(-1); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //把-1赋给串口操作句柄,并声明-1为DWord类型<br> &nbsp; &nbsp;m_SerialSet.BaudRate := CBR_9600; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //波特率默认值为9600<br> &nbsp; &nbsp;m_SerialSet.ByteSize := 8; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//数据位默认值为8<br> &nbsp; &nbsp;m_SerialSet.Parity := NOPARITY; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //校验方式默认值为无<br> &nbsp; &nbsp;m_SerialSet.StopBits := ONESTOPBIT; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//停止位默认值1<br> &nbsp; &nbsp;m_SerialSet.TimeOuts.ReadTotalTimeoutMultiplier := 0; //超时<br> &nbsp; &nbsp;m_SerialSet.TimeOuts.ReadTotalTimeoutConstant := 0; &nbsp; //超时<br> &nbsp; &nbsp;m_SerialSet.TimeOuts.ReadIntervalTimeout := MAXDWORD; //超时<br> &nbsp; &nbsp;m_Opened := FALSE; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //串口打开结果默认值为FALSE<br>end;

你这叫什么初始化啊？CREATE呢？我怎么没看到啊 ？

创建<br> &nbsp; &nbsp;Fm_handle := CreateFile(<br> &nbsp; &nbsp; &nbsp;PChar(Fm_sCom),<br> &nbsp; &nbsp; &nbsp;GENERIC_READ or GENERIC_WRITE,<br> &nbsp; &nbsp; &nbsp;0,<br> &nbsp; &nbsp; &nbsp;nil,<br> &nbsp; &nbsp; &nbsp;OPEN_EXISTING,<br> &nbsp; &nbsp; &nbsp;FILE_FLAG_OVERLAPPED,<br> &nbsp; &nbsp; &nbsp;0);<br>读<br> &nbsp; &nbsp; &nbsp;if not ReadFile(Fm_handle, pData[0], DataLen, DWord(iReceive), @Overlapped) and<br> &nbsp; &nbsp; &nbsp; &nbsp;(GetLastError &lt;&gt; ERROR_IO_PENDING) then<br> &nbsp; &nbsp; &nbsp; &nbsp;abort;<br>写<br> &nbsp; &nbsp; &nbsp;if not WriteFile(Fm_handle, pData[0], DataLen, dWord(iWrite), @Overlapped) and<br> &nbsp; &nbsp; &nbsp; &nbsp;(GetLastError &lt;&gt; ERROR_IO_PENDING) then<br> &nbsp; &nbsp; &nbsp; &nbsp;abort;

to 小虾米爱吃鱼, ：<br>我所说的初始化指的是使用Creatfile函数之前的配置。<br>请看清题意，我只有在刚刚开机的时候，程序运行出错，如果没有creatfile函数， 串口不可能打开的<br>function TSerialControl.OpenSerial(CommPort:string;ShareMode:Boolean=FALSE):Integer;<br>var<br> &nbsp;sCommPort:String;<br> &nbsp;dwShareModeWord;<br>begin<br> &nbsp;sCommPort:='//./'+CommPort; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//串口号由函数参数CommPort传递而来<br><br> &nbsp;if self.m_Opened Then &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //串口已被打开(被本程序打开过)<br> &nbsp;begin<br> &nbsp; &nbsp;Result:=-2;<br> &nbsp; &nbsp;Exit;<br> &nbsp;end;<br><br> &nbsp;if ShareMode Then &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //串口是否采用共享方式打开<br> &nbsp;begin<br> &nbsp; &nbsp;dwShareMode:=FILE_SHARE_READ;<br> &nbsp;end else<br> &nbsp;begin<br> &nbsp; &nbsp;dwShareMode:=0;<br> &nbsp;end;<br><br> &nbsp;m_hComm := CreateFile( &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//创建文件（串口），取得操作句柄<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;PChar(sCommPort), &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //文件名称<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//'//./COM10',<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;GENERIC_READ or GENERIC_WRITE, &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//操作方式(读或写)<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;dwShareMode, &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//共享方式<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;nil, &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//SD<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;OPEN_EXISTING, &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//文件创建方法<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;FILE_ATTRIBUTE_NORMAL, &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//文件属性<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //handle to template file<br><br> &nbsp;if( m_hComm = INVALID_HANDLE_VALUE ) then &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //串口打开失败<br> &nbsp;begin<br> &nbsp; &nbsp;Result:=-1;<br> &nbsp; &nbsp;Exit;<br> &nbsp;end;<br><br> &nbsp;self.m_Opened:=True; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//设置串口打开标志<br> &nbsp;Result:=0; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;//成功返回<br>end;

我自己认为问题应该出在前期各个参数的配置上， 或者，我的配置有遗漏， <br>我程序copy了我师兄的正常运行的unit单元，单元内主要定义了三个函数 ， OpenSerial ， writestring, readstring.<br>其中， readstring &nbsp;我在接收到数据后的处理上做了修改，而其他两个函数没变化<br>我确定以前的单元能够正查运行。<br>我修改的部分在 Readsuccess := ReadFile(m_hComm, &nbsp; &nbsp; &nbsp; &nbsp; //操作句柄<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;bStr[0], &nbsp; &nbsp; &nbsp; &nbsp;//数据缓冲区<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;NumberOfBytesToRead, &nbsp; //要读取的字节长度<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;iReadNum, &nbsp; &nbsp; &nbsp; &nbsp;//实际读取的字节长度<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;nil); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; //overlapped buffer<br>这个api 之后， 故障发生是 这个api函数的调用不返回，所以，我猜测可能是参数的配置问题，可又一时间想不到原因，请各位朋友帮我思考一下

顶

-------------------------------------------------------------------<br>如果我先用串口 调试工具打开某串口然后再关闭， 然后用我的程序调试，就能一直保持正常运行（不论我的程序开闭多少次，只要不重起电脑，就能正常运行）。<br>-------------------------------------------------------------------<br>这是因为某些状态位已经让调试工具帮你设定了，而你的程序在初始化时未做这些工作。<br><br>-------------------------------------------------------------------<br>我确定以前的单元能够正查运行。<br>-------------------------------------------------------------------<br>有时候看起来正确的东西其实亦可能具有它的偶然性，只是未暴露而已，尤其是程序的bug或defect。<br><br>跟读函数没关系，还是初始化的问题。另外，建议你使用第三方控件试试，你现在使用的这种方式如果需要细节控制可能比较困难。<br><br>以上纯属一家之言，仅供参考，如有错误，欢迎指正。

先谢谢 WickedladII 大哥的指点， 我也想到了是配置或者初始话的问题， 所以拿出来问大家，比如com口初始化需要注意哪几项什么的～！<br>我不能使用第三方控件，因为多数第三方控件是主动读串口的，我希望用的是我向串口写命令，然后等待命令的响应。<br>如果用主动读串口的方式，就复杂了，我得每次读到数据后，先检查上次是什么命令，然后再做处理，而且， 我用的是多线程，还得每个线程都建立一个窜口类<br>所以，希望能找到串口初始化时需要注意什么，单从学习知识的角度讲，我也愿意知道我程序不能工作的原因，而不是绕过它～！

你只打开了串口<br>你的那些参数应用到串口了吗<br>SetCommState<br>SetCommTimeOut等等

Mike1234567890 老兄说到了关键， 我又仔细检查一遍程序，发现了一个相当郁闷的错误，<br>修改了之后问题就解决了。可怜我的100分了心疼啊 。。。。。。。。。。。。。

多人接受答案了。