socket传输中判断数据流长度

Question

第一：ioctlsocket设定了非阻塞套接字后，accpet接收时未接收完会直接返回，而需要将剩下的数据接收完是否还要手动调用accept？还是只使用一次accept
第二：客户端send，服务器accept，怎么判断接收数据完整长度。。
（希望能简单给下这两个部分的代码）

Answer 1

如果是设置成非阻塞套接制，那你accept后还要用select看看是否有连接练过来，就是设个fd_set看它是否可读了。。你也可以设置成阻塞的，就少了select的步骤了。。我是这么想的。。
第二个问题，你在客户端发送时可以在数据的前是个字节放上数据长度totalLength，之后才是真是数据，然后服务端先读取一段数据，之后取出前是个字节的内容，然后就开始数数了，只memcpy totalLength个字节 代码 明天抽时间给你贴点  要给分的 

Answer 2

这相当于客户端的
                    int structureSize = sizeof(AlertDetail);
                    int alertXMLlength = 0;
                    int customResponseFieldlength = 0;
int AreaOfInterestEventSynopsisPointsLength = sizeof(Point)*detail->areaOfInterestEventSynopsis.pointsNum;
int AreaOfInterestEventSynopsisActionsLength = 50*detail->areaOfInterestEventSynopsis.ActionsNum;
                    int totalImageLength=detail->targetSlices.slice1.snapshotSize+detail->targetSlices.slice2.snapshotSize;
                    if (NULL!=detail->alertXML)
                    {
                        alertXMLlength = strlen(detail->alertXML);
                    }
                    if (NULL!=detail->customResponseField)
                    {
                        customResponseFieldlength=strlen(detail->customResponseField);
                    }
                    int totalLength = structureSize+totalImageLength+alertXMLlength+customResponseFieldlength+AreaOfInterestEventSynopsisPointsLength+AreaOfInterestEventSynopsisActionsLength+32;
                    char * alertData = new char[totalLength];
                    if(alertData)
                    {
                        if(detail->targetSlices.slice1.snapshotData.vt==(VT_ARRAY|VT_UI1))   
                        {
                            char*pBuf=NULL;;
                            SafeArrayAccessData(detail->targetSlices.slice1.snapshotData.parray,(void **)&pBuf);   
                            memcpy(alertData+32+structureSize,pBuf,detail->targetSlices.slice1.snapshotSize); 
                            SafeArrayUnaccessData(detail->targetSlices.slice1.snapshotData.parray);   
                        }                        if(detail->targetSlices.slice2.snapshotData.vt==(VT_ARRAY|VT_UI1))   
                        {
                            char*pBuf=NULL;;
                            SafeArrayAccessData(detail->targetSlices.slice2.snapshotData.parray,(void **)&pBuf);   
                            memcpy(alertData+32+structureSize+detail->targetSlices.slice1.snapshotSize,pBuf,detail->targetSlices.slice2.snapshotSize); 
                            SafeArrayUnaccessData(detail->targetSlices.slice2.snapshotData.parray);   
                        }                        memcpy(alertData,&totalLength,4);
                        memcpy(alertData+4,&structureSize,4);
                        memcpy(alertData+8,&(detail->targetSlices.slice1.snapshotSize),4);
                        memcpy(alertData+12,&(detail->targetSlices.slice2.snapshotSize),4);
                        memcpy(alertData+16,&alertXMLlength,4);
                        memcpy(alertData+20,&customResponseFieldlength,4);
memcpy(alertData+24,&AreaOfInterestEventSynopsisPointsLength,4);
memcpy(alertData+28,&AreaOfInterestEventSynopsisActionsLength,4);
                        memcpy(alertData+32,detail,structureSize);
                        //拷贝警告XML文本
                        int alertXMLOffset= 32+structureSize+detail->targetSlices.slice1.snapshotSize+detail->targetSlices.slice2.snapshotSize;;
                        if (NULL!=detail->alertXML)
                        {
                            memcpy(alertData+alertXMLOffset,detail->alertXML,alertXMLlength);
                        } int customResponseFieldOffset = alertXMLOffset+alertXMLlength;
                        if (NULL!=detail->customResponseField)
                        {
                            //拷贝自定义xml文本 
                            memcpy(alertData+customResponseFieldOffset,detail->customResponseField,customResponseFieldlength);
                        } if (strncmp(detail->eventType,"AreaOfInterestEventSynopsis",strlen("AreaOfInterestEventSynopsis"))==0)
{
if (NULL!=detail->areaOfInterestEventSynopsis.points&&NULL!=detail->areaOfInterestEventSynopsis.Actions
&&0!=AreaOfInterestEventSynopsisPointsLength&&0!=AreaOfInterestEventSynopsisActionsLength)
{
int AreaOfInterestEventSynopsisPointsOffset = customResponseFieldOffset+customResponseFieldlength;
memcpy(alertData+AreaOfInterestEventSynopsisPointsOffset,detail->areaOfInterestEventSynopsis.points,AreaOfInterestEventSynopsisPointsLength);
int AreaOfInterestEventSynopsisActionsOffset = AreaOfInterestEventSynopsisPointsOffset+AreaOfInterestEventSynopsisPointsLength;
memcpy(alertData+AreaOfInterestEventSynopsisActionsOffset,detail->areaOfInterestEventSynopsis.Actions[0],AreaOfInterestEventSynopsisActionsLength);
}
}
AlertDetail * aa= (AlertDetail*)(alertData+32);
                        //向客户端发送
                        for(int clientIndex =0;clientIndex<clientSocketList.size();clientIndex++)
                        {
                            SOCKET clientSocket = 0;
                            clientSocket = clientSocketList[clientIndex];
                            DataSend(clientSocket,alertData,totalLength);
                            Sleep(100);
                        }
                        
                        //Sleep(300);
                        delete []alertData;
                        alertData=NULL;

Answer 3

这相当于服务端的 
            while (1)
            {
                FD_ZERO(&Fd_Read);
                FD_SET(connectToServerSocket, &Fd_Read);
                int ret=0, nRecv=0;
                if (hasObtainedTotalCount&&(charReceived==totalcharCount))
                {
                    if (charReceived>0)
                    {
                        ifDataReceived = true;
                    }
                    break;
                }                ret = select(FD_SETSIZE, &Fd_Read, NULL, NULL, NULL);
                if(ret <= 0)
                {
                    if (charReceived>0)
                    {
                        ifDataReceived = true;
                    }
                    break;
                }                //从服务端接收数据
                if(FD_ISSET(connectToServerSocket, &Fd_Read))
                {
                    // printf("从客户端接受数据\n");
                    nRecv = recv(connectToServerSocket, RecvBuf, sizeof(RecvBuf), 0);
                    if(nRecv <= 0)
                    {
                        if (charReceived>0)
                        {
                            ifDataReceived = true;
                        }
                        //检测到断开连接后客户端自动重连  ret==1 nRecv小于0
                        //::MessageBox(NULL,"服务器断开，客户端服务线程退出","",0);
closesocket(connectToServerSocket);
if (NULL!=DataBufferReceivedData.ReceivedData)
{
delete []DataBufferReceivedData.ReceivedData;
DataBufferReceivedData.ReceivedData = NULL;
}
goto connect;
                    }                    if (NULL!=DataBufferReceivedData.ReceivedData)
                    {
//如果缓冲区不够，重新申请
if (charReceived+nRecv >= receiveBufferLength) 
{
int times = ((int)((charReceived+nRecv)/receiveBufferLength)+1)*3;
//内存空间增倍
tempBuffer = new char[receiveBufferLength * times];
memset(tempBuffer,0,receiveBufferLength * times);
memcpy(tempBuffer,DataBufferReceivedData.ReceivedData,charReceived);
receiveBufferLength = receiveBufferLength * times;
delete []DataBufferReceivedData.ReceivedData;
DataBufferReceivedData.ReceivedData = tempBuffer;
tempBuffer = NULL;
} //把当前收到数据追加到buffer末尾
memcpy(DataBufferReceivedData.ReceivedData+charReceived,RecvBuf,nRecv);
charReceived += nRecv;
//如果字符数大于260则取出在这里面的总字节数信息 以便看是否传送完成
if (!hasObtainedTotalCount&&charReceived>=16)
{
//取出0到3四个字节的总字节数信息
memcpy(&totalcharCount,DataBufferReceivedData.ReceivedData,sizeof(size_t));
hasObtainedTotalCount=true;
}
                    }
                }
            }            if (ifDataReceived)
            {
AlertReceived();
//::MessageBox(NULL,"收到数据，已经写入文件~~~","提示",0);
DWORD timerThreadId = 0;
//闪烁和声音提示  alreadyHasATimer和timerOver确保当已经有提示时如果再有警告来则不再提示
if (!alreadyHasATimer&&!timerOver)
{
alreadyHasATimer = true;
timerOver = false;
//线程实现 马上返回
CreateThread(NULL,NULL,TimerProc,(LPVOID)(0),0,&timerThreadId);
}
delete []DataBufferReceivedData.ReceivedData;
DataBufferReceivedData.ReceivedData=NULL;
            }
        }

Answer 4

wangxuqing大侠回答真完善。。谢谢啦，小小积分全给你了