Qt多线程 TCP 服务端

Qt实现 多线程 TCP 服务端

因为项目中要用到TCP客户端的并发处理，所以TCP服务端用多线程去实现是必要的。于是花了一大早上的时间写了一各Demo
如图：

主要关键代码：

1. 关于线程的处理。关于线程的理论知识，本人在上一篇《多线程简单举例》中已经介绍过了，这里不多解释了。这里重点关注run()函数的消息处理。

#include "tcpserverthread.h"

serverThread::serverThread(int sockDesc, QObject *parent) :
    QThread(parent),
    m_sockDesc(sockDesc)
{
     connect(this, SIGNAL(clientconnected(QString)), this, SLOT(connectToHost(QString)));
    // connect(m_tcpsocket, SIGNAL(sigDisconnectAll()), this, SLOT(disconnectAll()));

}

serverThread::~serverThread()
{
    m_socket->close();
}

void serverThread::run(void)
{
    m_socket = new MySocket(m_sockDesc);

    if (!m_socket->setSocketDescriptor(m_sockDesc)) {
        return ;
    }

    QString ip = m_socket->peerAddress().toString();

    int port =  m_socket->peerPort();

    strIP = QString("%1:%2").arg(ip).arg(QString ::number(port));

    emit testsignal(strIP);

    emit clientconnected(strIP);


    //断开
    connect(m_socket, &MySocket::disconnected, this, &serverThread::disconnectToHost);
    //接收
    connect(m_socket, SIGNAL(dataReady(const QString&, const QByteArray&)),
            this, SLOT(recvDataSlot(const QString&, const QByteArray&)));
    //发送
    connect(this, SIGNAL(sendData(int, QString,const QByteArray&)),
            m_socket, SLOT(sendData(int,QString, const QByteArray&)));

   // connect(m_socket, SIGNAL(aboutToClose()), thread, SLOT(deleteLater()));

    this->exec();
}

//mainwindows 窗口会发送socket发送信号，接收信号并处理
void serverThread::sendDataSlot(int sockDesc, QString str, const QByteArray &data)
{
    if (data.isEmpty()) {
        return ;
    }

    emit sendData(sockDesc, str,data);
}

void serverThread::recvDataSlot(const QString &ip, const QByteArray &data)
{
    emit dataReady(ip, data);
}

void serverThread::disconnectToHost(void)
{
    emit disconnectTCP(m_sockDesc,strIP);
    m_socket->disconnectFromHost();
    this->quit();

}

void serverThread::connectToHost(QString str)
{
   emit connectTCP(m_sockDesc,str);

}

2、tcpServer端对接入客户端需要重写 函数incomingConnection（）

This virtual function is called by QLocalServer when a new connection is available. socketDescriptor is the native socket descriptor for the accepted connection.
The base implementation creates a QLocalSocket, sets the socket descriptor and then stores the QLocalSocket in an internal list of pending connections. Finally newConnection() is emitted.
Reimplement this function to alter the server’s behavior when a connection is available.

void MyTcpServer::incomingConnection(int sockDesc)
{
    m_socketList.append(sockDesc);

    serverThread *thread = new serverThread(sockDesc);


    //显示连接数
    connect(thread, SIGNAL(connectTCP(int,QString )), m_Widget, SLOT(showConCont(int,QString)));
    //显示客户端IP
    connect(thread, SIGNAL(connectTCP(int,QString )), m_Widget, SLOT(showConnection(int,QString)));
    connect(thread, SIGNAL(disconnectTCP(int,QString)), m_Widget, SLOT(showDisconnection(int,QString)));

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



    //接收数据
    connect(thread, SIGNAL(dataReady(const QString&, const QByteArray&)),
            m_Widget, SLOT(recvData(const QString&, const QByteArray&)));
    //发送数据
    connect(m_Widget, SIGNAL(sendData(int,QString, const QByteArray&)),
            thread, SLOT(sendDataSlot(int,QString, const QByteArray&)));

    thread->start();
}

3、为了增加代码的可读性，这里新建一个类mysocket 来单独收发数据

//发送数据
void MySocket::sendData(int id, QString str,const QByteArray &data)
{
    QString ip = peerAddress().toString();

    int port =  peerPort();

    ip = QString("%1:%2").arg(ip).arg(QString ::number(port));

    if(str == ip)
    {
        if (!data.isEmpty()) {
            this->write(data);
        }
    }
}

void MySocket::recvData(void)
{
    QString ip = peerAddress().toString();

    int port =  peerPort();

    ip = QString("%1:%2").arg(ip).arg(QString ::number(port));

    QByteArray data = readAll();

    emit dataReady(ip, data);
}

本示例下载地址：https://download.csdn.net/download/qq_21291397/12364249

总结：
TCP 服务端的创建不难，重点还是要理解多线程的那层含义。实操动手写一写代码，可以提高对多线程的理解。