QT开发实战精解5.3局域网聊天系统 文件传输时一直处于等待的状态

Question

完全按照书本例子写的码，问题是传输文件时一直处于等待状态，无论是本机发往本机还是不同主机之间都不成功。不明白是哪里出问题，求大神解答！代码如下，如果觉得看起来麻烦可以问我要工程文件调试，感激不尽！

widget.cpp:

#include "widget.h"
#include "ui_widget.h"
#include <QUdpSocket>
#include <QHostInfo>
#include <QMessageBox>
#include <QScrollBar>
#include <QDateTime>
#include <QNetworkInterface>
#include <QProcess>

#include "tcpserver.h"
#include "tcpclient.h"
#include <QFileDialog>

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);

    udpSocket = new QUdpSocket(this);
    port = 45454;
    udpSocket->bind(port, QUdpSocket::ShareAddress | QUdpSocket::ReuseAddressHint);
    connect(udpSocket, SIGNAL(readyRead()), this, SLOT(processPendingDatagrams()));
    sendMessage(NewParticipant);

    server = new TcpServer(this);
    connect(server, SIGNAL(sendFileName(QString)), this, SLOT(getFileName(QString)));
}

Widget::~Widget()
{
    delete ui;
}

// 使用UDP广播发送信息
void Widget::sendMessage(MessageType type, QString serverAddress)
{
    QByteArray data;
    QDataStream out(&data, QIODevice::WriteOnly);
    QString localHostName = QHostInfo::localHostName();
    QString address = getIP();
    out << type << getUserName() << localHostName;

    switch(type)
    {
    case Message :
        if (ui->messageTextEdit->toPlainText() == "") {
            QMessageBox::warning(0,tr("警告"),tr("发送内容不能为空"),QMessageBox::Ok);
            return;
        }
        out << address << getMessage();
        ui->messageBrowser->verticalScrollBar()
                ->setValue(ui->messageBrowser->verticalScrollBar()->maximum());
        break;

    case NewParticipant :
        out << address;
        break;

    case ParticipantLeft :
        break;

    case FileName : {
        int row = ui->userTableWidget->currentRow();
        QString clientAddress = ui->userTableWidget->item(row, 2)->text();
        out << address << clientAddress << fileName;
        break;
    }

    case Refuse :
        out << serverAddress;
        break;
    }
    udpSocket->writeDatagram(data,data.length(),QHostAddress::Broadcast, port);
}

// 接收UDP信息
void Widget::processPendingDatagrams()
{
    while(udpSocket->hasPendingDatagrams())
    {
        QByteArray datagram;
        datagram.resize(udpSocket->pendingDatagramSize());
        udpSocket->readDatagram(datagram.data(), datagram.size());
        QDataStream in(&datagram, QIODevice::ReadOnly);
        int messageType;
        in >> messageType;
        QString userName,localHostName,ipAddress,message;
        QString time = QDateTime::currentDateTime()
                .toString("yyyy-MM-dd hh:mm:ss");

        switch(messageType)
        {
        case Message:
            in >> userName >> localHostName >> ipAddress >> message;
            ui->messageBrowser->setTextColor(Qt::blue);
            ui->messageBrowser->setCurrentFont(QFont("Times New Roman",12));
            ui->messageBrowser->append("[ " +userName+" ] "+ time);
            ui->messageBrowser->append(message);
            break;

        case NewParticipant:
            in >>userName >>localHostName >>ipAddress;
            newParticipant(userName,localHostName,ipAddress);
            break;

        case ParticipantLeft:
            in >>userName >>localHostName;
            participantLeft(userName,localHostName,time);
            break;

        case FileName: {
            in >> userName >> localHostName >> ipAddress;
            QString clientAddress, fileName;
            in >> clientAddress >> fileName;
            hasPendingFile(userName, ipAddress, clientAddress, fileName);
            break;
        }

        case Refuse: {
            in >> userName >> localHostName;
            QString serverAddress;
            in >> serverAddress;
            QString ipAddress = getIP();

            if(ipAddress == serverAddress)
            {
                server->refused();
            }
            break;
        }
        }
    }
}

// 处理新用户加入
void Widget::newParticipant(QString userName, QString localHostName, QString ipAddress)
{
    bool isEmpty = ui->userTableWidget->findItems(localHostName, Qt::MatchExactly).isEmpty();
    if (isEmpty) {
        QTableWidgetItem *user = new QTableWidgetItem(userName);
        QTableWidgetItem *host = new QTableWidgetItem(localHostName);
        QTableWidgetItem *ip = new QTableWidgetItem(ipAddress);

        ui->userTableWidget->insertRow(0);
        ui->userTableWidget->setItem(0,0,user);
        ui->userTableWidget->setItem(0,1,host);
        ui->userTableWidget->setItem(0,2,ip);
        ui->messageBrowser->setTextColor(Qt::gray);
        ui->messageBrowser->setCurrentFont(QFont("Times New Roman",10));
        ui->messageBrowser->append(tr("%1 在线！").arg(userName));
        ui->userNumLabel->setText(tr("在线人数：%1").arg(ui->userTableWidget->rowCount()));

        sendMessage(NewParticipant);
    }
}

// 处理用户离开
void Widget::participantLeft(QString userName, QString localHostName, QString time)
{
    int rowNum = ui->userTableWidget->findItems(localHostName, Qt::MatchExactly).first()->row();
    ui->userTableWidget->removeRow(rowNum);
    ui->messageBrowser->setTextColor(Qt::gray);
    ui->messageBrowser->setCurrentFont(QFont("Times New Roman", 10));
    ui->messageBrowser->append(tr("%1 于 %2 离开！").arg(userName).arg(time));
    ui->userNumLabel->setText(tr("在线人数：%1").arg(ui->userTableWidget->rowCount()));
}

// 获取ip地址
QString Widget::getIP()
{
    QList<QHostAddress> list = QNetworkInterface::allAddresses();
    foreach (QHostAddress address, list) {
        if(address.protocol() == QAbstractSocket::IPv4Protocol)
            return address.toString();
    }
    return 0;
}

// 获取用户名
QString Widget::getUserName()
{
    QStringList envVariables;
    envVariables << "USERNAME.*" << "USER.*" << "USERDOMAIN.*"
                 << "HOSTNAME.*" << "DOMAINNAME.*";
    QStringList environment = QProcess::systemEnvironment();
    foreach (QString string, envVariables) {
        int index = environment.indexOf(QRegExp(string));
        if (index != -1) {
            QStringList stringList = environment.at(index).split('=');
            if (stringList.size() == 2) {
                return stringList.at(1);
                break;
            }
        }
    }
    return "unknown";
}

// 获得要发送的消息
QString Widget::getMessage()
{
    QString msg = ui->messageTextEdit->toHtml();

    ui->messageTextEdit->clear();
    ui->messageTextEdit->setFocus();
    return msg;
}


// 发送消息
void Widget::on_sendButton_clicked()
{
    sendMessage(Message);
}




// 获取要发送的文件名
void Widget::getFileName(QString name)
{
    fileName = name;
    sendMessage(FileName);
}

// 传输文件按钮
void Widget::on_sendToolBtn_clicked()
{
    if(ui->userTableWidget->selectedItems().isEmpty())
    {
        QMessageBox::warning(0, tr("选择用户"),
                       tr("请先从用户列表选择要传送的用户！"), QMessageBox::Ok);
        return;
    }
    server->show();
    server->initServer();
}

// 是否接收文件
void Widget::hasPendingFile(QString userName, QString serverAddress,
                            QString clientAddress, QString fileName)
{
    QString ipAddress = getIP();
    if(ipAddress == clientAddress)
    {
        int btn = QMessageBox::information(this,tr("接受文件"),
                                           tr("来自%1(%2)的文件：%3,是否接收？")
                                           .arg(userName).arg(serverAddress).arg(fileName),
                                           QMessageBox::Yes,QMessageBox::No);
        if (btn == QMessageBox::Yes) {
            QString name = QFileDialog::getSaveFileName(0,tr("保存文件"),fileName);
            if(!name.isEmpty())
            {
                TcpClient *client = new TcpClient(this);
                client->setFileName(name);
                client->setHostAddress(QHostAddress(serverAddress));
                client->show();
            }
        } else {
            sendMessage(Refuse, serverAddress);
        }
    }
}






tcpserver.cpp:

#include "tcpserver.h"
#include "ui_tcpserver.h"

#include <QFile>
#include <QTcpServer>
#include <QTcpSocket>
#include <QMessageBox>
#include <QFileDialog>
#include <QDebug>

TcpServer::TcpServer(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::TcpServer)
{
    ui->setupUi(this);

    setFixedSize(350,180);

    tcpPort = 6666;
    tcpServer = new QTcpServer(this);
    connect(tcpServer, SIGNAL(newConnection()), this, SLOT(sendMessage()));

    initServer();
}

TcpServer::~TcpServer()
{
    delete ui;
}

// 初始化
void TcpServer::initServer()
{
    payloadSize = 64*1024;
    TotalBytes = 0;
    bytesWritten = 0;
    bytesToWrite = 0;

    ui->serverStatusLabel->setText(tr("请选择要传送的文件"));
    ui->progressBar->reset();
    ui->serverOpenBtn->setEnabled(true);
    ui->serverSendBtn->setEnabled(false);

    tcpServer->close();
}

// 开始发送数据
void TcpServer::sendMessage()
{
    ui->serverSendBtn->setEnabled(false);
    clientConnection = tcpServer->nextPendingConnection();
    connect(clientConnection, SIGNAL(bytesWritten(qint64)),
            this, SLOT(updateClientProgress(qint64)));

    ui->serverStatusLabel->setText(tr("开始传送文件 %1 ！").arg(theFileName));

    localFile = new QFile(fileName);
    if(!localFile->open((QFile::ReadOnly))){
        QMessageBox::warning(this, tr("应用程序"), tr("无法读取文件 %1:\n%2")
                             .arg(fileName).arg(localFile->errorString()));
        return;
    }
    TotalBytes = localFile->size();
    QDataStream sendOut(&outBlock, QIODevice::WriteOnly);
    sendOut.setVersion(QDataStream::Qt_4_7);
    time.start();  // 开始计时
    QString currentFile = fileName.right(fileName.size()
                                         - fileName.lastIndexOf('/')-1);
    sendOut << qint64(0) << qint64(0) << currentFile;
    TotalBytes += outBlock.size();
    sendOut.device()->seek(0);
    sendOut << TotalBytes << qint64((outBlock.size() - sizeof(qint64)*2));
    bytesToWrite = TotalBytes - clientConnection->write(outBlock);
    outBlock.resize(0);
}

// 更新进度条
void TcpServer::updateClientProgress(qint64 numBytes)
{
    qApp->processEvents();
    bytesWritten += (int)numBytes;
    if (bytesToWrite > 0) {
        outBlock = localFile->read(qMin(bytesToWrite, payloadSize));
        bytesToWrite -= (int)clientConnection->write(outBlock);
        outBlock.resize(0);
    } else {
        localFile->close();
    }
    ui->progressBar->setMaximum(TotalBytes);
    ui->progressBar->setValue(bytesWritten);

    float useTime = time.elapsed();
    double speed = bytesWritten / useTime;
    ui->serverStatusLabel->setText(tr("已发送 %1MB (%2MB/s) "
                   "\n共%3MB 已用时:%4秒\n估计剩余时间：%5秒")
                   .arg(bytesWritten / (1024*1024))
                   .arg(speed*1000 / (1024*1024), 0, 'f', 2)
                   .arg(TotalBytes / (1024 * 1024))
                   .arg(useTime/1000, 0, 'f', 0)
                   .arg(TotalBytes/speed/1000 - useTime/1000, 0, 'f', 0));

    if(bytesWritten == TotalBytes) {
        localFile->close();
        tcpServer->close();
        ui->serverStatusLabel->setText(tr("传送文件 %1 成功").arg(theFileName));
    }
}

// 打开按钮
void TcpServer::on_serverOpenBtn_clicked()
{
    fileName = QFileDialog::getOpenFileName(this);
    if(!fileName.isEmpty())
    {
        theFileName = fileName.right(fileName.size() - fileName.lastIndexOf('/')-1);
        ui->serverStatusLabel->setText(tr("要传送的文件为：%1 ").arg(theFileName));
        ui->serverSendBtn->setEnabled(true);
        ui->serverOpenBtn->setEnabled(false);
    }
}

// 发送按钮
void TcpServer::on_serverSendBtn_clicked()
{
    if(!tcpServer->listen(QHostAddress::Any,tcpPort))//开始监听
    {
        qDebug() << tcpServer->errorString();
        close();
        return;
    }

    ui->serverStatusLabel->setText(tr("等待对方接收... ..."));
    emit sendFileName(theFileName);
}

// 关闭按钮
void TcpServer::on_serverCloseBtn_clicked()
{
    if(tcpServer->isListening())
    {
        tcpServer->close();
        if (localFile->isOpen())
            localFile->close();
        clientConnection->abort();
    }
    close();
}

// 被对方拒绝
void TcpServer::refused()
{
    tcpServer->close();
    ui->serverStatusLabel->setText(tr("对方拒绝接收！！！"));
}

// 关闭事件
void TcpServer::closeEvent(QCloseEvent *)
{
    on_serverCloseBtn_clicked();
}






tcpclient.cpp

#include "tcpclient.h"
#include "ui_tcpclient.h"

#include <QTcpSocket>
#include <QDebug>
#include <QMessageBox>

TcpClient::TcpClient(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::TcpClient)
{
    ui->setupUi(this);

    setFixedSize(350,180);

    TotalBytes = 0;
    bytesReceived = 0;
    fileNameSize = 0;

    tcpClient = new QTcpSocket(this);
    tcpPort = 6666;
    connect(tcpClient, SIGNAL(readyRead()), this, SLOT(readMessage()));
    connect(tcpClient, SIGNAL(error(QAbstractSocket::SocketError)), this,
            SLOT(displayError(QAbstractSocket::SocketError)));
}

TcpClient::~TcpClient()
{
    delete ui;
}

// 设置文件名
void TcpClient::setFileName(QString fileName)
{
    localFile = new QFile(fileName);
}

// 设置地址
void TcpClient::setHostAddress(QHostAddress address)
{
    hostAddress = address;
    newConnect();
}

// 创建新连接
void TcpClient::newConnect()
{
    blockSize = 0;
    tcpClient->abort();
    tcpClient->connectToHost(hostAddress, tcpPort);
    time.start();
}

// 读取数据
void TcpClient::readMessage()
{
    QDataStream in(tcpClient);
    in.setVersion(QDataStream::Qt_4_7);

    float useTime = time.elapsed();

    if (bytesReceived <= sizeof(qint64)*2) {
        if ((tcpClient->bytesAvailable()
             >= sizeof(qint64)*2) && (fileNameSize == 0))
        {
            in>>TotalBytes>>fileNameSize;
            bytesReceived += sizeof(qint64)*2;
        }
        if((tcpClient->bytesAvailable() >= fileNameSize) && (fileNameSize != 0)){
            in>>fileName;
            bytesReceived +=fileNameSize;

            if(!localFile->open(QFile::WriteOnly)){
                QMessageBox::warning(this,tr("应用程序"),tr("无法读取文件 %1:\n%2.")
                                     .arg(fileName).arg(localFile->errorString()));
                return;
            }
        } else {
            return;
        }
    }
    if (bytesReceived < TotalBytes) {
        bytesReceived += tcpClient->bytesAvailable();
        inBlock = tcpClient->readAll();
        localFile->write(inBlock);
        inBlock.resize(0);
    }
    ui->progressBar->setMaximum(TotalBytes);
    ui->progressBar->setValue(bytesReceived);

    double speed = bytesReceived / useTime;
    ui->tcpClientStatusLabel->setText(tr("已接收 %1MB (%2MB/s) "
                                         "\n共%3MB 已用时:%4秒\n估计剩余时间：%5秒")
                                      .arg(bytesReceived / (1024*1024))
                                      .arg(speed*1000/(1024*1024),0,'f',2)
                                      .arg(TotalBytes / (1024 * 1024))
                                      .arg(useTime/1000,0,'f',0)
                                      .arg(TotalBytes/speed/1000 - useTime/1000,0,'f',0));

    if(bytesReceived == TotalBytes)
    {
        localFile->close();
        tcpClient->close();
        ui->tcpClientStatusLabel->setText(tr("接收文件 %1 完毕")
                                          .arg(fileName));
    }
}

// 错误处理
void TcpClient::displayError(QAbstractSocket::SocketError socketError)
{
    switch(socketError)
    {
    case QAbstractSocket::RemoteHostClosedError : break;
    default : qDebug() << tcpClient->errorString();
    }
}

// 取消按钮
void TcpClient::on_tcpClientCancleBtn_clicked()
{
    tcpClient->abort();
    if (localFile->isOpen())
        localFile->close();
}

// 关闭按钮
void TcpClient::on_tcpClientCloseBtn_clicked()
{
    tcpClient->abort();
    if (localFile->isOpen())
        localFile->close();
    close();
}

// 关闭事件
void TcpClient::closeEvent(QCloseEvent *)
{
    on_tcpClientCloseBtn_clicked();
}

Answer 1

防火墙有没有彻底关闭
QString ipAddress = getIP();
这里的ip是多少，调试或者输出看下
服务器和客户端在同一个电脑上运行，端口是否冲突