基于QT的多线程服务器

// thread.cpp

#include "thread.h"

Thread::Thread(int socketDescriptor, QObject *parent)

    : QThread(parent)

{

    m_socketDescriptor = socketDescriptor;

}

Thread::~Thread()

{

}

void Thread::run()

{

    m_tcpSocket = new QTcpSocket;

    if (!m_tcpSocket->setSocketDescriptor(m_socketDescriptor))

    {

        emit error(m_tcpSocket->error());

        return;

    }

    connect(m_tcpSocket,SIGNAL(readyRead()),this, SLOT(readData_slot()), Qt::DirectConnection); // Qt::DirectConnection线程内传递消

    connect(m_tcpSocket, SIGNAL(error(QAbstractSocket::SocketError)), this, SLOT(tcpSocket_error_slot()));

    connect(m_tcpSocket,SIGNAL(disconnected()),this,SLOT(quit()));//socket断开连接，线程退出

    qDebug() << "run" << m_tcpSocket->peerAddress().toString();

    qDebug() << "run" << m_tcpSocket->peerPort();

    exec();

}

void Thread::readData_slot()

{

    QDataStream in(m_tcpSocket);

    in.setVersion(QDataStream::Qt_5_0);

    QDataStream out(m_tcpSocket);

    out.setVersion(QDataStream::Qt_5_0);

    QString data;

    in >> data;

    qDebug() << "readData_slot" << data;

    data = "hello this is server";

    out << data;

    qDebug() << data;

}

void Thread::tcpSocket_error_slot()

{

    qDebug() << m_tcpSocket->errorString();

}

// server.cpp

#include "server.h"

Server::Server(QObject *parent)

    : QTcpServer(parent)

{

}

Server::~Server()

{

}

void Server::incomingConnection(qintptr socketDescriptor)

{

    Thread *thread = new Thread(socketDescriptor, this);

    connect(thread, SIGNAL(finished()), thread, SLOT(deleteLater()));

    thread->start();

}

// dialog.cpp

#include "dialog.h"

Dialog::Dialog(QWidget *parent)

    : QWidget(parent)

{

    m_statusLabel = new QLabel;

    m_statusLabel->setWordWrap(true);

    m_quitButton = new QPushButton(tr("Quit"));

    m_quitButton->setAutoDefault(false);

    QString ipAddress;

    QList<QHostAddress> ipAddressesList = QNetworkInterface::allAddresses();

    // use the first non-localhost IPv4 address

    for (int i=0; i <ipAddressesList.size(); ++i)

    {

        if (ipAddressesList.at(i) != QHostAddress::LocalHost &&

            ipAddressesList.at(i).toIPv4Address())

        {

            ipAddress = ipAddressesList.at(i).toString();

            break;

        }

    }

    // if we did not find one, use IPv4 localhost

    if (ipAddress.isEmpty())

    {

        ipAddress = QHostAddress(QHostAddress::LocalHost).toString();

    }

    m_statusLabel->setText(tr("The server is running on\n\nIP: %1\nport: %2\n\n"

                            "Run the Client example now.")

                         .arg(ipAddress).arg(m_server.serverPort()));

    connect(m_quitButton, SIGNAL(clicked()), this, SLOT(close()));

    QHBoxLayout *buttonLayout = new QHBoxLayout;

    buttonLayout->addStretch(1);

    buttonLayout->addWidget(m_quitButton);

    buttonLayout->addStretch(1);

    QVBoxLayout *mainLayout = new QVBoxLayout;

    mainLayout->addWidget(m_statusLabel);

    mainLayout->addLayout(buttonLayout);

    setLayout(mainLayout);

    setWindowTitle(tr("Threaded Server"));

    if (!m_server.listen(QHostAddress::Any, 1314))

    {

        QMessageBox::critical(this, tr("Threaded Server"),

                              tr("Unable to start the server: %1.")

                              .arg(m_server.errorString()));

        close();

        return;

    }

}

Dialog::~Dialog()

{

}

这是我参照http://m.blog.csdn.net/blog/sdu_sky/8104175这位大神的博客和QT的多线程服务器源码写出来的，

但是我又两个地方不明白，在dialog.cpp中

if (!m_server.listen(QHostAddress::Any, 1314))

这一句怎样就能在监听成功之后创建一个新的线程，

void Server::incomingConnection(qintptr socketDescriptor)
还有这个函数没有在构造函数里实现，也没有显式的调用？？？这是怎么回事，望高手指导