Qt5 基于TCP传输的发送/接收文件服务器(支持多客户端)

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一、实现功能
1、服务器端选择待发送的文件,可以是多个
2、开启服务器,支持多客户端接入,能够实时显示每个客户端接入状态
3、等待所有客户端都处于已连接状态时,依次发送文件集给每个客户端,显示每个客户端发送进度
4、发送完成后等待接收客户端发回的文件,显示接收进度
5、关闭服务器


二、实现要点
先讲一下实现上述功能的几个关键点,明白的这几个要点,功能的大框架就搭好了,细节在下一节再讲


1、新建服务器类testServer,继承自QTcpServer
功能:用于接收客户端TCP请求,存储所有客户端信息,向主窗口发送信息
在这个类中实例化QTcpServer的虚函数:
void incomingConnection(int socketDescriptor); //虚函数,有tcp请求时会触发
 
参数为描述socket ID的int变量
此函数在QTcpServer检测到外来TCP请求时,会自动调用。

注:若要接收局域网内的TCP请求,连接newConnection信号到自定义槽函数
connect(tcpServer,SIGNAL(newConnection()),this,SLOT(acceptConnection()));
但是这种方法无法处理多客户端


2、新建客户端类testClient,继承自QTcpSocket
功能:存储每个接入的客户端信息,控制发送/接收文件,向testServer发送信息

在testServer的incomingConnection函数中,通过设置socketDescriptor,初始化一个testClient实例

testClient *socket = new testClient(this);if (!socket->setSocketDescriptor(socketDescriptor)){    emit error(socket->error());    return;}

3、发送数据
实例化testClient类,通过void writeData(const char * data, qint64 size)函数将数据写入TCP流

testClient *a;a->writeData("message",8);

一般来说,使用QByteArray和QDataStream进行格式化的数据写入,设置流化数据格式类型为QDataStream::Qt_5_0,与客户端一致

testClient *a;QByteArray outBlock;       //缓存一次发送的数据QDataStream sendOut(&outBlock, QIODevice::WriteOnly);//数据流sendOut.setVersion(QDataStream::Qt_5_0);sendOut << "message";a->writeData(outBlock,outBlock.size());outBlock.resize(0);

注意outBlock如果为全局变量,最后需要resize,否则下一次写入时会出错


在testClient构造函数中连接数据成功发送后产生的bytesWritten()信号

connect(this, SIGNAL(bytesWritten(qint64)), this, SLOT(updateClientProgress(qint64)));

参数为成功写入TCP流的字节数
通过捕获这个信号,可以实现数据的连续发送。因为发送文件时,数据是一块一块发送的,比如设定一块的大小为20字节,那么发送完20字节,怎么继续发送呢?就靠的是这个函数,再用全局变量记录下总共发送的字节数,便可以控制发送的结束。


4、发送文件
先把文件读到QFile变量中,再通过QBytesArray发送

testClient *a;QFile sendFile = new QFile(sendFilePath);//读取发送文件路径if (!sendFile->open(QFile::ReadOnly ))  //读取发送文件{    return;}QByteArray outBlock;outBlock = sendFile->read(sendFile.size());a->writeData(outBlock,outBlock.size());


5、接收数据
依旧是testClient类,连接有readyRead()信号,readyRead()信号为新连接中有可读数据时发出

connect(this, SIGNAL(readyRead()), this, SLOT(recvData()));

首先将testClient连接实例(如testClient *a)封装到QDataStream变量中,设置流化数据格式类型为QDataStream::Qt_5_0,与客户端一致。
在读入数据前,用a->bytesAvailable()检测数据流中可读入的字节数,然后就可以通过"<<"操作符读入数据了。

QDataStream in(a); //本地数据流in.setVersion(QDataStream::Qt_5_0); //设置流版本,以防数据格式错误quint8 receiveClass;if(this->bytesAvailable() >= (sizeof(quint8))){        in >> receiveClass;}

6、接收文件
使用readAll读入TCP流中所有数据,再写入到QFile变量中

QByteArray inBlock;inBlock = a->readAll();//读入所有数据QFile receivedFile = new QFile(receiveFilePath);//打开接收文件if (!receivedFile->open(QFile::WriteOnly )){    return;}QFile receivedFile->write(inBlock);//写入文件inBlock.resize(0);


三、具体实现
1、全局定义
需要定义一些全局变量和常量,定义如下

//存储文件路径和文件名的结构体struct openFileStruct{    QString filePath;    QString fileName;};struct clientInfo   //客户端信息{    QString ip;     //ip    int state;      //状态    QString id;     //id};const quint8 sendtype_file = 0;    //发送类型是文件const quint8 sendtype_start_test = 10;    //发送类型是开始测试const quint8 sendtype_msg = 20;    //发送类型是消息const quint16 filetype_list = 0;    //文件类型为列表const quint16 filetype_wavfile = 1;    //文件类型为wav文件const QString clientStatus[7] =    //客户端状态    {QObject::tr("Unconnected"),QObject::tr("HostLookup"),QObject::tr("Connecting"),        QObject::tr("Connected"),QObject::tr("Bound"),QObject::tr("Listening"),QObject::tr("Closing")};
openFileStruct 用于主窗口,存储发送文件的路径和文件名
clientInfo 用于主窗口,存储每个客户端的信息
规定传输协议为先发送一个quint8的标志位,规定传输类型,即为sendtype定义的部分
sendtype为0时,发送文件。filetype为文件类型
发送文件协议为:发送类型 | 数据总大小 | 文件类型 | 文件名大小 | 文件名 | 文件内容
发送文件时,先发送一个文件列表,每行一个文件名,再逐个发送文件
clientStatus为客户端状态,与Qt内部的socket status定义相同


2、testClient类
一个testClient类实例为一个socket客户端描述
(1)类声明:

class testClient : public QTcpSocket{    Q_OBJECTpublic:    testClient(QObject *parent = 0);    int num;    //客户端序号    void prepareTransfer(std::vector<openFileStruct>& openFileList,int testtype_t);    //准备传输文件signals:    void newClient(QString, int, int);  //客户端信息变更信号    void outputlog(QString);    //输出日志信息    void updateProgressSignal(qint64,qint64,int);   //更新发送进度信号    void newClientInfo(QString,int,int);  //更新客户端信息private slots:    void recvData();    //接收数据    void clientConnected();     //已连接    void clientDisconnected();  //断开连接    void newState(QAbstractSocket::SocketState);    //新状态    void startTransfer(const quint16);    //开始传输文件    void updateClientProgress(qint64 numBytes);  //发送文件内容    void getSendFileList(QString path);     //在指定路径生成发送文件列表    quint64 getSendTotalSize();    //获取sendFilePath对应文件加上头的大小private:    //发送文件所需变量    qint64  loadSize;          //每次接收的数据块大小    qint64  TotalSendBytes;        //总共需发送的字节数    qint64  bytesWritten;      //已发送字节数    qint64  bytesToWrite;      //待发送字节数    QString sendFileName;          //待发送的文件的文件名    QString sendFilePath;          //待发送的文件的文件路径    QFile *sendFile;          //待发送的文件    QByteArray outBlock;       //缓存一次发送的数据    int sendNum;        //记录当前发送到第几个文件    int sendFileNum;    //记录发送文件个数    int totalSendSize;  //记录发送文件总大小    quint64 proBarMax;  //发送进度条最大值    quint64 proBarValue;    //进度条当前值    std::vector<openFileStruct> openList;   //发送文件列表    //接收文件用变量    quint8 receiveClass;        //0:文件,1:开始测试,20:客户端接收到文件反馈    quint16 fileClass;          //待接收文件类型    qint64 TotalRecvBytes;          //总共需接收的字节数    qint64 bytesReceived;       //已接收字节数    qint64 fileNameSize;        //待接收文件名字节数    QString receivedFileName;   //待接收文件的文件名    QFile *receivedFile;        //待接收文件    QByteArray inBlock;         //接收临时存储块    qint64 totalBytesReceived;  //接收的总大小    qint32 recvNum;       //现在接收的是第几个    quint64 recvFileNum;         //接收文件个数    quint64 totalRecvSize;    //接收文件总大小    bool isReceived[3];     //是否收到客户端的接收文件反馈    };

public为需要上层访问的公有变量和函数
signals为向上层发送的信号,保证主窗口实时显示信息
private slots包括底层实现发送、接收消息的函数,以及信号处理的槽
private为私有变量,包括发送文件和接收文件所需的变量


(2)类定义:
构造函数:

testClient::testClient(QObject *parent) :    QTcpSocket(parent){    //发送变量初始化    num = -1;    loadSize = 100*1024;    openList.clear();    //接收变量初始化    TotalRecvBytes = 0;    bytesReceived = 0;    fileNameSize = 0;    recvFileNum = 0;    totalRecvSize = 0;    totalBytesReceived = 0;    recvNum = 0;    receiveClass = 255;    fileClass = 0;    for(int i=0; i<3; i++)        isReceived[i] = false;    //连接信号和槽    connect(this, SIGNAL(readyRead()), this, SLOT(recvData()));    connect(this, SIGNAL(disconnected()), this, SLOT(clientDisconnected()));    connect(this, SIGNAL(stateChanged(QAbstractSocket::SocketState)),            this, SLOT(newState(QAbstractSocket::SocketState)));    connect(this, SIGNAL(bytesWritten(qint64)), this, SLOT(updateClientProgress(qint64)));}

初始化变量
连接qt的tcp信号和自定义槽,包括:
readyRead() 接收消息信号
disconnected() 断开连接信号
stateChanged(QAbstractSocket::SocketState) 连接状态变更信号
bytesWritten(qint64) 已写入发送消息流信号
 


接收数据槽,设定服务器只接收一个文件:

void testClient::recvData()     //接收数据,服务器只接收客户端的一个结果文件{    QDataStream in(this); //本地数据流    in.setVersion(QDataStream::Qt_5_0); //设置流版本,以防数据格式错误    QString unit;    qint32 msg;    if(bytesReceived <= (sizeof(quint8)))    {        if(this->bytesAvailable() >= (sizeof(quint8)))        {            in >> receiveClass;        }        switch(receiveClass)        {        case sendtype_file:     //接收文件            bytesReceived += sizeof(quint8);            qDebug() << "bytesReceived: " << bytesReceived;            break;        case sendtype_msg:            in >> msg;            if(msg == 0)//接收文件列表            {                emit outputlog(tr("client %1 have received list file")                               .arg(this->peerAddress().toString()));            }            else if(msg == 1)   //接收文件            {                emit outputlog(tr("client %1 have received file(s)")                               .arg(this->peerAddress().toString()));            }            return;        default:            return;        }    }    if(bytesReceived >= (sizeof(quint8)) && bytesReceived <= (sizeof(quint8) + sizeof(qint64)*2 + sizeof(quint16)))   //开始接收文件,先接受报头    {        //收3个int型数据,分别存储总长度、文件类型和文件名长度        if( ( this->bytesAvailable() >= (sizeof(qint64)*2 + sizeof(quint16)) ) && (fileNameSize == 0) )        {            in >> TotalRecvBytes >> fileClass >> fileNameSize;            bytesReceived += sizeof(qint64)*2;  //收到多少字节            bytesReceived += sizeof(quint16);            if(fileClass == filetype_result)            {                recvNum = 1;                recvFileNum = 1;                totalRecvSize = TotalRecvBytes;  //只有一个文件,文件总大小为该文件发送大小                totalBytesReceived += sizeof(qint64)*2;                totalBytesReceived += sizeof(quint16);                totalBytesReceived += sizeof(quint8);                emit newClientInfo(tr("receiving result"),num,4);            }            else            {                QMessageBox::warning(NULL,tr("WARNING"),tr("client %1 send wrong type of file to server")                                     .arg(this->peerAddress().toString()));                return;            }        }        //接着收文件名并建立文件        if((this->bytesAvailable() >= fileNameSize)&&(fileNameSize != 0))        {            in >> receivedFileName;            bytesReceived += fileNameSize;            totalBytesReceived += fileNameSize;            QString receiveFilePath = receive_path + "/" + receivedFileName;    //接收文件路径            emit outputlog(tr("receive from client %1\nsave as:%2")                           .arg(this->peerAddress().toString())                           .arg(receiveFilePath));            //建立文件            receivedFile = new QFile(receiveFilePath);            if (!receivedFile->open(QFile::WriteOnly ))            {                QMessageBox::warning(NULL, tr("WARNING"),                                     tr("cannot open file %1:\n%2.").arg(receivedFileName).arg(receivedFile->errorString()));                return;            }        }        else        {            return;        }    }    //一个文件没有接受完    if (bytesReceived < TotalRecvBytes)    {        //可用内容比整个文件长度-已接收长度短,则全部接收并写入文件        qint64 tmp_Abailable = this->bytesAvailable();        if(tmp_Abailable <= (TotalRecvBytes - bytesReceived))        {            bytesReceived += tmp_Abailable;            totalBytesReceived += tmp_Abailable;            inBlock = this->readAll();            receivedFile->write(inBlock);            inBlock.resize(0);            tmp_Abailable = 0;        }        //可用内容比整个文件长度-已接收长度长,则接收所需内容,并写入文件        else        {            inBlock = this->read(TotalRecvBytes - bytesReceived);            if(fileClass == filetype_wavfile)            {                totalBytesReceived += (TotalRecvBytes - bytesReceived);            }            bytesReceived = TotalRecvBytes;            receivedFile->write(inBlock);            inBlock.resize(0);            tmp_Abailable = 0;        }    }    emit updateProgressSignal(totalBytesReceived,totalRecvSize,num);   //更新发送进度信号    //善后:一个文件全部收完则重置变量关闭文件流,删除指针    if (bytesReceived == TotalRecvBytes)    {        //变量重置        TotalRecvBytes = 0;        bytesReceived = 0;        fileNameSize = 0;        receiveClass = 255;        receivedFile->close();        delete receivedFile;        //输出信息        emit outputlog(tr("Have received file: %1 from client %2")                       .arg(receivedFileName)                       .arg(this->peerAddress().toString()));   //log information        //全部文件接收完成        if(recvNum == recvFileNum)        {            //变量重置            recvFileNum = 0;            recvNum = 0;            totalBytesReceived = 0;            totalRecvSize = 0;            emit outputlog(tr("Receive all done!"));        }        if(fileClass == filetype_result)        {            emit newClientInfo(tr("Evaluating"),num,4);        }    }}
接收文件时,需要一步一步判断接收字节是否大于协议的下一项,若大于则再判断其值
接收的文件类型必须是filetype_result
未接收完记录接收进度
接收完文件进行善后,关闭文件流删除指针等
每进行完一步,向上层发送信号,包括客户端信息和接收进度
 


更新客户端状态函数,向上层发送信号

void testClient::newState(QAbstractSocket::SocketState state)    //新状态{    emit newClient(this->peerAddress().toString(), (int)state, num);}
发送的信号参数为:该客户端IP,状态序号,客户端编号
 


开始传输文件函数(发送包含文件信息的文件头)

void testClient::startTransfer(const quint16 type)    //开始传输文件{    TotalSendBytes = 0;    //总共需发送的字节数    bytesWritten = 0;       //已发送字节数    bytesToWrite = 0;       //待发送字节数    //开始传输文件信号    emit outputlog(tr("start sending file to client: %1\n filename: %2")                   .arg(this->peerAddress().toString())                   .arg(sendFileName));    sendFile = new QFile(sendFilePath);    if (!sendFile->open(QFile::ReadOnly ))  //读取发送文件    {        QMessageBox::warning(NULL, tr("WARNING"),                             tr("can not read file %1:\n%2.")                             .arg(sendFilePath)                             .arg(sendFile->errorString()));        return;    }    TotalSendBytes = sendFile->size();    QDataStream sendOut(&outBlock, QIODevice::WriteOnly);    sendOut.setVersion(QDataStream::Qt_5_0);    //写入发送类型,数据大小,文件类型,文件名大小,文件名    sendOut << quint8(0) << qint64(0) << quint16(0) << qint64(0) << sendFileName;    TotalSendBytes +=  outBlock.size();    sendOut.device()->seek(0);    sendOut << quint8(sendtype_file)<< TotalSendBytes << quint16(type)            << qint64((outBlock.size() - sizeof(qint64) * 2) - sizeof(quint16) - sizeof(quint8));    this->writeData(outBlock,outBlock.size());    //this->flush();    bytesToWrite = TotalSendBytes - outBlock.size();    outBlock.resize(0);}
读取发送文件
建立发送文件头
用writeData将文件头写入TCP发送流,记录已发送字节数


发送文件内容:
void testClient::updateClientProgress(qint64 numBytes)  //发送文件内容{    if(TotalSendBytes == 0)        return;    bytesWritten += (int)numBytes;    proBarValue += (int)numBytes;    emit updateProgressSignal(proBarValue,proBarMax,num);   //更新发送进度信号    if (bytesToWrite > 0)    {        outBlock = sendFile->read(qMin(bytesToWrite, loadSize));        bytesToWrite -= (int)this->writeData(outBlock,outBlock.size());        outBlock.resize(0);    }    else    {        sendFile->close();        //结束传输文件信号        if(TotalSendBytes < 1024)        {            emit outputlog(tr("finish sending file to client: %1\n filename: %2 %3B")                           .arg(this->peerAddress().toString())                           .arg(sendFileName)                           .arg(TotalSendBytes));        }        else if(TotalSendBytes < 1024*1024)        {            emit outputlog(tr("finish sending file to client: %1\n filename: %2 %3KB")                           .arg(this->peerAddress().toString())                           .arg(sendFileName)                           .arg(TotalSendBytes / 1024.0));        }        else        {            emit outputlog(tr("finish sending file to client: %1\n filename: %2 %3MB")                           .arg(this->peerAddress().toString())                           .arg(sendFileName)                           .arg(TotalSendBytes / (1024.0*1024.0)));        }            if(sendNum < openList.size())   //还有文件需要发送            {                if(sendNum == 0)                {                    //QFile::remove(sendFilePath);    //删除列表文件                    proBarMax = totalSendSize;                    proBarValue = 0;                }                sendFilePath = openList[sendNum].filePath;                sendFileName = openList[sendNum].fileName;                sendNum++;                startTransfer(filetype_wavfile);            }            else    //发送结束            {                emit newClientInfo(tr("send complete"),num,4);                TotalSendBytes = 0;    //总共需发送的字节数                bytesWritten = 0;       //已发送字节数                bytesToWrite = 0;       //待发送字节数            }    }}
文件未发送完:记录发送字节数,writeData继续发送,writeData一旦写入发送流,自动又进入updateClientProgress函数
文件已发送完:发出信号,检测是否还有文件需要发送,若有则调用startTransfer继续发送,若没有则发出信号,更新客户端信息
 


准备传输文件函数,被上层调用,参数为发送文件列表:

void testClient::prepareTransfer(std::vector<openFileStruct>& openFileList)    //准备传输文件{    if(openFileList.size() == 0)    //没有文件    {        return;    }    testtype_now = testtype_t;    isSendKeyword = false;    for(int i=0; i<2; i++)        isReceived[i] = false;    openList.clear();    openList.assign(openFileList.begin(),openFileList.end());   //拷贝文件列表    QString sendFileListName = "sendFileList.txt";    QString sendFileListPath = temp_Path + "/" + sendFileListName;    getSendFileList(sendFileListPath);     //在指定路径生成发送文件列表    emit newClientInfo(tr("sending test files"),num,4);   //更新主窗口测试阶段        sendFilePath = sendFileListPath;        sendFileName = sendFileListName;        sendNum = 0;    //发送到第几个文件        proBarMax = getSendTotalSize();        proBarValue = 0;        startTransfer(filetype_list);    //开始传输文件}
拷贝文件列表
生成发送文件列表文件
更新主窗口信息
开始传输列表文件
 


上面调用的生成列表文件函数如下:

void testClient::getSendFileList(QString path)     //在指定路径生成发送文件列表{    sendFileNum = openList.size();    //记录发送文件个数    totalSendSize = 0;  //记录发送文件总大小    for(int i = 0; i < sendFileNum; i++)    {        sendFileName = openList[i].fileName;        sendFilePath = openList[i].filePath;        totalSendSize += getSendTotalSize();    }    FILE *fp;    fp = fopen(path.toLocal8Bit().data(),"w");    fprintf(fp,"%d\n",sendFileNum);    fprintf(fp,"%d\n",totalSendSize);    for(int i = 0; i < sendFileNum; i++)    {        fprintf(fp,"%s\n",openList[i].fileName.toLocal8Bit().data());    }    fclose(fp);}


被上面调用getSendTotalSize函数如下:

quint64 testClient::getSendTotalSize()    //获取sendFilePath对应文件加上头的大小{    int totalsize;    //计算列表文件及文件头总大小    QFile *file = new QFile(sendFilePath);    if (!file->open(QFile::ReadOnly ))  //读取发送文件    {        QMessageBox::warning(NULL, tr("WARNING"),                             tr("can not read file %1:\n%2.")                             .arg(sendFilePath)                             .arg(file->errorString()));        return 0;    }    totalsize = file->size();  //文件内容大小    QDataStream sendOut(&outBlock, QIODevice::WriteOnly);    sendOut.setVersion(QDataStream::Qt_5_0);    //写入发送类型,数据大小,文件类型,文件名大小,文件名    sendOut << quint8(0) << qint64(0) << quint16(0) << qint64(0) << sendFileName;    totalsize +=  outBlock.size();  //文件头大小    file->close();    outBlock.resize(0);    return totalsize;}



3、testServer类
一个testClient类实例为一个socket服务器端描述
(1)类声明:

class testServer : public QTcpServer{    Q_OBJECTpublic:    testServer(QObject *parent = 0);    std::vector<testClientp> clientList;     //客户端tcp连接    std::vector<QString> ipList;    //客户端ip    int totalClient;  //客户端数protected:    void incomingConnection(int socketDescriptor);  //虚函数,有tcp请求时会触发signals:    void error(QTcpSocket::SocketError socketError);    //错误信号    void newClientSignal(QString clientIP,int state,int threadNum);   //将新客户端信息发给主窗口    void updateProgressSignal(qint64,qint64,int);   //更新发送进度信号    void outputlogSignal(QString);  //发送日志消息信号    void newClientInfoSignal(QString,int,int);    //更新客户端信息public slots:    void newClientSlot(QString clientIP,int state,int threadNum);   //将新客户端信息发给主窗口    void updateProgressSlot(qint64,qint64,int);   //更新发送进度槽    void outputlogSlot(QString);        //发送日志消息槽    void newClientInfoSlot(QString,int,int);      //更新客户端信息private:    int getClientNum(testClientp socket); //检测用户,若存在,返回下标,若不存在,返回用户数};
public:需要主窗口访问的变量
incomingConnection:接收tcp请求
signals:发送客户端信息的信号
public slots:接收下层testClient信号的槽,并向上层主窗口发送信号
private:检测用户是否存在的辅助函数
 


(2)类定义:
构造函数:

testServer::testServer(QObject *parent) :    QTcpServer(parent){    totalClient = 0;    clientList.clear();    ipList.clear();}



接收tcp请求函数:

void testServer::incomingConnection(int socketDescriptor){    testClient *socket = new testClient(this);    if (!socket->setSocketDescriptor(socketDescriptor))    {        QMessageBox::warning(NULL,"ERROR",socket->errorString());        emit error(socket->error());        return;    }    int num = getClientNum(socket); //检测用户,若存在,返回下标,若不存在,返回用户数    socket->num = num;  //记录序号    emit newClientSignal(socket->peerAddress().toString(),(int)socket->state(),num);   //将新客户端信息发给主窗口    //连接信号和槽    connect(socket, SIGNAL(newClient(QString,int,int)), this, SLOT(newClientSlot(QString,int,int)));    connect(socket, SIGNAL(outputlog(QString)), this, SLOT(outputlogSlot(QString)));    connect(socket, SIGNAL(updateProgressSignal(qint64,qint64,int)),            this, SLOT(updateProgressSlot(qint64,qint64,int)));    connect(socket, SIGNAL(newClientInfo(QString,int,int)),            this, SLOT(newClientInfoSlot(QString,int,int)));    connect(socket, SIGNAL(readyToTest(int,int)), this, SLOT(readyToTestSlot(int,int)));    connect(socket, SIGNAL(startEvaluate(int,QString)), this, SLOT(startEvaluateSlot(int,QString)));    connect(socket, SIGNAL(evaluateComplete(int,QString,int)),            this, SLOT(evaluateCompleteSlot(int,QString,int)));    if(num == totalClient)        totalClient++;}
通过setSocketDescriptor获取当前接入的socket描述符
检测用户是否存在,记录序号
向主窗口发送信号,连接下层testClient信号和接收槽
更新客户端总数


 
检测用户是否存在的函数

int testServer::getClientNum(testClientp socket) //检测用户,若存在,返回下标,若不存在,加入列表{    for(int i = 0; i < ipList.size(); i++)    {        qDebug() << "No." << i << "ip: " << ipList[i];        if(ipList[i] == socket->peerAddress().toString())        {            clientList[i] = socket;            return i;        }    }    clientList.push_back(socket);   //存入客户列表    ipList.push_back(socket->peerAddress().toString()); //存入ip列表    return totalClient;}
其他发送信号的函数均为连接下层和上层的中转,由于比较简单就不赘述了
 
 
4、主窗口
在主窗口(继承自QMainWindow)绘制所需控件:
lineEdit_ipaddress:显示服务器IP
lineEdit_port:设置服务器端口
listWidget_sendwav:发送文件列表
tableWidget_clientlist:客户端信息列表,显示所有客户端IP,接入状态,发送/接收进度条
textEdit_status:状态栏
pushButton_addwav:添加发送文件按钮
pushButton_deletewav:删除发送文件按钮
pushButton_startserver:开启/关闭服务器按钮
pushButton_senddata:发送数据按钮
pushButton_deleteclient:删除客户端按钮


主窗口需定义的变量
testServer *tcpServer;  //tcp服务器指针bool isServerOn;    //服务器是否开启std::vector<openFileStruct> openFileList; //存储目录和文件名对


开启/关闭服务器按钮

void testwhynot::on_pushButton_startserver_clicked()    //开启服务器{    if(isServerOn == false)    {        tcpServer = new testServer(this);        ui->comboBox_testtype->setEnabled(false);   //开启服务器后不能更改测试类型        ui->pushButton_addwav->setEnabled(false);   //不能更改wav列表        ui->pushButton_deletewav->setEnabled(false);        //监听本地主机端口,如果出错就输出错误信息,并关闭        if(!tcpServer->listen(QHostAddress::Any,ui->lineEdit_port->text().toInt()))        {            QMessageBox::warning(NULL,"ERROR",tcpServer->errorString());            return;        }        isServerOn = true;        ui->pushButton_startserver->setText(tr("close server"));        //显示到状态栏        ui->textEdit_status->append(tr("%1 start server: %2:%3")                                    .arg(getcurrenttime())                                    .arg(ipaddress)                                    .arg(ui->lineEdit_port->text()));        //链接错误处理信号和槽        //connect(this,SIGNAL(error(int,QString)),this,SLOT(displayError(int,QString)));        //处理多客户端,连接从客户端线程发出的信号和主窗口的槽        //连接客户端信息更改信号和槽        connect(tcpServer,SIGNAL(newClientSignal(QString,int,int)),this,SLOT(acceptNewClient(QString,int,int)));        //连接日志消息信号和槽        connect(tcpServer,SIGNAL(outputlogSignal(QString)),                this,SLOT(acceptOutputlog(QString)));        //连接更新发送进度信号和槽        connect(tcpServer, SIGNAL(updateProgressSignal(qint64,qint64,int)),                this, SLOT(acceptUpdateProgress(qint64,qint64,int)));        //连接更新客户端信息列表信号和槽        connect(tcpServer, SIGNAL(newClientInfoSignal(QString,int,int)),                this, SLOT(acceptNewClientInfo(QString,int,int)));        //显示到状态栏        ui->textEdit_status->append(tr("%1 wait for client...")                                    .arg(getcurrenttime()));    }    else    {        isServerOn = false;        ui->pushButton_startserver->setText(tr("start server"));        //断开所有客户端连接,发出disconnected()信号         for(int i=0; i<tcpServer->clientList.size(); i++)        {            if(ui->tableWidget_clientlist->item(i,2)->text() == clientStatus[3])    //处于连接状态才断开,否则无法访问testClientp指针              {                testClientp p = tcpServer->clientList[i];                   p->close();            }        }        //清空列表         tcpServer->clientList.clear();        tcpServer->ipList.clear();        clientInfoList.clear();        for(int i=0; i<ui->tableWidget_clientlist->rowCount(); )            ui->tableWidget_clientlist->removeRow(i);        tcpServer->close(); //关闭服务器        ui->textEdit_status->append(tr("%1 clost server.").arg(getcurrenttime()));        ui->comboBox_testtype->setEnabled(true);    //可以重新选择测试类型        ui->pushButton_addwav->setEnabled(true);   //能更改wav列表        ui->pushButton_deletewav->setEnabled(true);        //按钮无效化        ui->pushButton_senddata->setEnabled(false);        ui->pushButton_starttest->setEnabled(false);        ui->pushButton_deleteclient->setEnabled(false);    }}
注意:
1、listen(“监听类型”,“端口号”) 用于开启服务器,在指定端口监听客户端连接
2、connect连接了客户端更新信息的信号,来自下层testServer类


发送数据按钮
void testwhynot::on_pushButton_senddata_clicked()   //发送数据{    //多客户端发送数据    if(ui->comboBox_testtype->currentIndex() == testtype_keyword)    {        if(!check_file(keyword_filepath))            return;    }    vector<clientInfo>::iterator it;    //遍历所有客户端信息,确保都处于“已连接”状态    for(it=clientInfoList.begin(); it!=clientInfoList.end(); it++)    {        if((*it).state != 3)   //有客户端未处于“已连接”状态        {            QMessageBox::warning(this,tr("WARNING"),tr("client %1 is not connected.").arg((*it).ip));            return;        }    }    //没有文件    if(openFileList.size() == 0)    {        QMessageBox::warning(NULL,tr("WARNING"),tr("no file! can not send!"));        return;    }    for(int i = 0; i < tcpServer->clientList.size(); i++)    {        tcpServer->clientList[i]->prepareTransfer(openFileList,ui->comboBox_testtype->currentIndex());    }    //按钮无效化    ui->pushButton_senddata->setEnabled(false);}
调用底层prepareTransfer函数开始传输


删除客户端按钮
void testwhynot::on_pushButton_deleteclient_clicked(){    QList<QTableWidgetItem*> list = ui->tableWidget_clientlist->selectedItems();   //读取所有被选中的item    if(list.size() == 0)    //没有被选中的就返回    {        QMessageBox::warning(this,QObject::tr("warning"),QObject::tr("please select a test client"));        return;    }    std::set<int> del_row;   //记录要删除的行号,用set防止重复    for(int i=0; i<list.size(); i++)    //删除选中的项    {        QTableWidgetItem* sel = list[i]; //指向选中的item的指针        if (sel)        {            int row = ui->tableWidget_clientlist->row(sel);   //获取行号            del_row.insert(row);        }    }    std::vector<int> del_list;  //赋值给del_list,set本身为有序    for(std::set<int>::iterator it=del_row.begin(); it!=del_row.end(); it++)    {        del_list.push_back(*it);    }    for(int i=del_list.size()-1; i>=0; i--)    //逆序遍历    {        testClientp p = tcpServer->clientList[del_list[i]];        p->close();        ui->tableWidget_clientlist->removeRow(del_list[i]);   //从显示列表中删除行        clientInfoList.erase(clientInfoList.begin() + del_list[i]); //从内部列表删除        tcpServer->ipList.erase(tcpServer->ipList.begin() + del_list[i]);        tcpServer->clientList.erase(tcpServer->clientList.begin() + del_list[i]);        tcpServer->totalClient--;    }    for(int i=0; i<tcpServer->clientList.size(); i++)    {        tcpServer->clientList[i]->num = i;    }    if(clientInfoList.empty())  //没有客户端,删除按钮无效化    {        ui->pushButton_deleteclient->setEnabled(false);    }}
删除客户端较麻烦,由于支持多选删除,需要先将选中的行号排序、去重、从大到小遍历删除(防止删除后剩余行号变化)
不仅要关闭客户端,还要将其从显示列表和内部列表删除,保持显示和实际列表同步




上述便是基于tcp传输的发送/接收服务器端的搭建,客户端只需遵从上述的发送协议搭建即可,客户端发送与接收与服务器基本相同,也不赘述了。
 
本文偏重于工程实现,Qt的TCP传输原理叙述不多,若要深入了解qt套接字编程,请参考:http://cool.worm.blog.163.com/blog/static/64339006200842922851118/