QT网络编程Tcp下C/S架构的即时通信

先写一个客户端，实现简单的，能加入聊天，以及加入服务器的界面。

#ifndef TCPCLIENT_H
#define TCPCLIENT_H

#include <QDialog>
#include <QListWidget>
#include <QLineEdit>
#include <QPushButton>
#include <QLabel>
#include <QGridLayout>
#include <QtNetWork/QHostAddress>
#include <QtNetWork/QTcpSocket>

class TcpClient : public QDialog
{
    Q_OBJECT

public:
    TcpClient(QWidget *parent = 0,Qt::WindowFlags f=0);
    ~TcpClient();
private:
    QListWidget *contentListWidget;
    QLineEdit *sendLineEdit;
    QPushButton *sendBtn;
    QLabel *userNameLabel;
    QLineEdit *userNameLineEdit;
    QLabel *serverIPLabel;
    QLineEdit *serverIPLineEdit;
    QLabel *portLabel;
    QLineEdit *portLineEdit;
    QPushButton *enterBtn;
    QGridLayout *mainLayout;
    bool status;
    int port;
    QHostAddress *serverIP;
    QString userName;
    QTcpSocket *tcpSocket;
public slots:
    void slotEnter();
    void slotConnected();
    void slotDisconnected();
    void dataReceived();
    void slotSend();
};

#endif // TCPCLIENT_H

　　有一个加入服务器的按钮，还有一个发送消息的按钮，在头文件，先定义两个函数。

#include "tcpclient.h"
#include <QMessageBox>
#include <QHostInfo>

TcpClient::TcpClient(QWidget *parent,Qt::WindowFlags f)
    : QDialog(parent,f)
{
    setWindowTitle(tr("TCP Client"));

    contentListWidget = new QListWidget;

    sendLineEdit = new QLineEdit;
    sendBtn = new QPushButton(tr("send"));

    userNameLabel = new QLabel(tr("name"));
    userNameLineEdit = new QLineEdit;

    serverIPLabel = new QLabel(tr("server"));
    serverIPLineEdit = new QLineEdit;

    portLabel = new QLabel(tr("port"));
    portLineEdit = new QLineEdit;

    enterBtn= new QPushButton(tr("join chat"));

    mainLayout = new QGridLayout(this);
    mainLayout->addWidget(contentListWidget,0,0,1,2);
    mainLayout->addWidget(sendLineEdit,1,0);
    mainLayout->addWidget(sendBtn,1,1);
    mainLayout->addWidget(userNameLabel,2,0);
    mainLayout->addWidget(userNameLineEdit,2,1);
    mainLayout->addWidget(serverIPLabel,3,0);
    mainLayout->addWidget(serverIPLineEdit,3,1);
    mainLayout->addWidget(portLabel,4,0);
    mainLayout->addWidget(portLineEdit,4,1);
    mainLayout->addWidget(enterBtn,5,0,1,2);

    status = false;

    port = 8010;
    portLineEdit->setText(QString::number(port));

    serverIP =new QHostAddress();

    connect(enterBtn,SIGNAL(clicked()),this,SLOT(slotEnter()));
    connect(sendBtn,SIGNAL(clicked()),this,SLOT(slotSend()));

    sendBtn->setEnabled(false);
}

TcpClient::~TcpClient()
{

}

void TcpClient::slotEnter()
{
    if(!status)
    {
        QString ip = serverIPLineEdit->text();
        if(!serverIP->setAddress(ip))
        {
            QMessageBox::information(this,tr("error"),tr("server ip address error!"));
            return;
        }

        if(userNameLineEdit->text()=="")
        {
            QMessageBox::information(this,tr("error"),tr("User name error!"));
            return;
        }

        userName=userNameLineEdit->text();

        tcpSocket = new QTcpSocket(this);
        connect(tcpSocket,SIGNAL(connected()),this,SLOT(slotConnected()));
        connect(tcpSocket,SIGNAL(disconnected()),this,SLOT(slotDisconnected()));
        connect(tcpSocket,SIGNAL(readyRead()),this,SLOT(dataReceived()));

        tcpSocket->connectToHost(*serverIP,port);

        status=true;
    }
    else
    {
        int length=0;
        QString msg=userName+tr(":Leave Chat Room");
        if((length=tcpSocket->write(msg.toLatin1(),msg.length()))!=msg. length())
        {
            return;
        }

        tcpSocket->disconnectFromHost();

        status=false;
    }
}

void TcpClient::slotConnected()
{
    sendBtn->setEnabled(true);
    enterBtn->setText(tr("离开"));

    int length=0;
    QString msg=userName+tr(":Enter Chat Room");
    if((length=tcpSocket->write(msg.toLatin1(),msg.length()))!=msg.length())
    {
        return;
    }
}

void TcpClient::slotSend()
{
    if(sendLineEdit->text()=="")
    {
        return ;
    }

    QString msg=userName+":"+sendLineEdit->text();

    tcpSocket->write(msg.toLatin1(),msg.length());
    sendLineEdit->clear();
}

void TcpClient::slotDisconnected()
{
    sendBtn->setEnabled(false);
    enterBtn->setText(tr("join chat"));
}

void TcpClient::dataReceived()
{
    while(tcpSocket->bytesAvailable()>0)
    {
        QByteArray datagram;
        datagram.resize(tcpSocket->bytesAvailable());

        tcpSocket->read(datagram.data(),datagram.size());

        QString msg=datagram.data();
        contentListWidget->addItem(msg.left(datagram.size()));
    }
}

实现界面布局。在Enter槽函数中，确定加入还是离开的服务器的功能。如果加入了，就将消息，写到tcpsocket中，构造消。

服务端的头文件：

#ifndef TCPSERVER_H
#define TCPSERVER_H

#include <QDialog>
#include <QListWidget>
#include <QLabel>
#include <QLineEdit>
#include <QPushButton>
#include <QGridLayout>
#include "server.h"

class TcpServer : public QDialog
{
    Q_OBJECT

public:
    TcpServer(QWidget *parent = 0,Qt::WindowFlags f=0);
    ~TcpServer();
private:
    QListWidget *ContentListWidget;
    QLabel *PortLabel;
    QLineEdit *PortLineEdit;
    QPushButton *CreateBtn;
    QGridLayout *mainLayout;
    int port;
    Server *server;
public slots:
    void slotCreateServer();
    void updateServer(QString,int);
};

#endif // TCPSERVER_H

　这是服务端的界面的，把消息显示而已。实现这个布局。

#include "tcpserver.h"

TcpServer::TcpServer(QWidget *parent,Qt::WindowFlags f)
    : QDialog(parent,f)
{
    setWindowTitle(tr("TCP Server"));

    ContentListWidget = new QListWidget;

    PortLabel = new QLabel(tr(" port"));
    PortLineEdit = new QLineEdit;

    CreateBtn = new QPushButton(tr("create chat"));
    mainLayout = new QGridLayout(this);
    mainLayout->addWidget(ContentListWidget,0,0,1,2);
    mainLayout->addWidget(PortLabel,1,0);
    mainLayout->addWidget(PortLineEdit,1,1);
    mainLayout->addWidget(CreateBtn,2,0,1,2);

    port=8010;
    PortLineEdit->setText(QString::number(port));

    connect(CreateBtn,SIGNAL(clicked()),this,SLOT(slotCreateServer()));
}

TcpServer::~TcpServer()
{

}

void TcpServer::slotCreateServer()
{
    server = new Server(this,port);
    connect(server,SIGNAL(updateServer(QString,int)),this,SLOT(updateServer(QString,int)));

    CreateBtn->setEnabled(false);
}

void TcpServer::updateServer(QString msg,int length)
{
    ContentListWidget->addItem(msg.left(length));
}

　创建TCP的套接字，以便实现服务端和客户端的通信。

#ifndef TCPCLIENTSOCKET_H
#define TCPCLIENTSOCKET_H

#include <QtNetWork/QTcpSocket>
#include <QObject>

class TcpClientSocket : public QTcpSocket
{
    Q_OBJECT
public:
    TcpClientSocket();
signals:
    void updateClients(QString,int);
    void disconnected(int);
protected slots:
    void dataReceived();
    void slotDisconnected();
};

#endif // TCPCLIENTSOCKET_H

　　以上是头文件，具体的是：

#include "tcpclientsocket.h"

TcpClientSocket::TcpClientSocket()
{
    connect(this,SIGNAL(readyRead()),this,SLOT(dataReceived()));
    connect(this,SIGNAL(disconnected()),this,SLOT(slotDisconnected()));
}

void TcpClientSocket::dataReceived()
{
    while(bytesAvailable()>0)
    {
        int length = bytesAvailable();
        char buf[1024];
        read(buf,length);

        QString msg=buf;
        emit updateClients(msg,length);
    }
}

void TcpClientSocket::slotDisconnected()
{
    emit disconnected(this->socketDescriptor());
}

　　实现服务器，头文件：

#ifndef SERVER_H
#define SERVER_H

#include <QtNetWork/QTcpServer>
#include <QObject>
#include "tcpclientsocket.h"

class Server : public QTcpServer
{
    Q_OBJECT
public:
    Server(QObject *parent=0,int port=0);
    QList<TcpClientSocket*> tcpClientSocketList;
signals:
    void updateServer(QString,int);
public slots:
    void updateClients(QString,int);
    void slotDisconnected(int);
protected:
    void incomingConnection(int socketDescriptor);
};

#endif // SERVER_H

　　

#include "server.h"

Server::Server(QObject *parent,int port)
    :QTcpServer(parent)
{
    listen(QHostAddress::Any,port);
}

void Server::incomingConnection(int socketDescriptor)
{
    TcpClientSocket *tcpClientSocket = new TcpClientSocket;
    connect(tcpClientSocket,SIGNAL(updateClients(QString,int)),this,SLOT(updateClients(QString,int)));
    connect(tcpClientSocket,SIGNAL(disconnected(int)),this,SLOT(slotDisconnected(int)));

    tcpClientSocket->setSocketDescriptor(socketDescriptor);

    tcpClientSocketList.append(tcpClientSocket);
}

void Server::updateClients(QString msg,int length)
{
    emit updateServer(msg,length);
    for(int i=0;i<tcpClientSocketList.count();i++)
    {
        QTcpSocket *item = tcpClientSocketList.at(i);
        if(item->write(msg.toLatin1(),length)!=length)
        {
            continue;
        }
    }
}

void Server::slotDisconnected(int descriptor)
{
    for(int i=0;i<tcpClientSocketList.count();i++)
    {
        QTcpSocket *item = tcpClientSocketList.at(i);
        if(item->socketDescriptor()==descriptor)
        {
            tcpClientSocketList.removeAt(i);
            return;
        }
    }
    return;
}

　　实现后的界面：