71-TCP协议工作原理及实战

一服务器端



#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTcpServer> // 专门用于建立TCP连接并传输数据信息
#include <QtNetwork> // 此模块提供开发TCP/IP客户端和服务器的类

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;

    // 自定义如下
private:
    QTcpServer *tcpserver; //TCP服务器
    QTcpSocket *tcpsocket;// TCP通讯socket
    QString GetLocalIpAddress(); // 获取本机的IP地址

private slots:
    void clientconnect();
    void clientdisconnect();
    void socketreaddata();
    void newconnection();
    void on_pushButton_Start_clicked();
    void on_pushButton_Stop_clicked();
    void on_pushButton_Send_clicked();
protected:
    void closeEvent(QCloseEvent *event);
};
#endif // MAINWINDOW_H




***************************************************************
***************************************************************
mainwindow.cpp


#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QMessageBox>

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


    //测试是否获取本地地址
    QString strip = GetLocalIpAddress();
    QMessageBox::information(this,"数据",strip,QMessageBox::Yes);

    //添加到comboxip里面
    ui->comboBoxIp->addItem(strip);


    //调用监听
    tcpserver = new QTcpServer(this);
    connect(tcpserver,SIGNAL(newConnection()),this,SLOT(newconnection()));

}

MainWindow::~MainWindow()
{
    delete ui;
}
// 获取本机的IP地址
QString MainWindow::GetLocalIpAddress()
{
    QString hostname=QHostInfo::localHostName();
    QHostInfo hostinfo=QHostInfo::fromName(hostname);

    QString localip="";
    QList<QHostAddress> addresslist=hostinfo.addresses();
    if(!addresslist.isEmpty())
    {
        for (int i=0;i<addresslist.count();i++)
        {
            QHostAddress addrhost=addresslist.at(i);
            if(QAbstractSocket::IPv4Protocol==addrhost.protocol())
            {
                localip=addrhost.toString();
                break;
            }

        }
    }
    return localip;
}

void MainWindow::clientconnect()
{
    //客户端连接
    ui->plainTextEdit_DispMsg->appendPlainText("****客户端套接字socket连接****");
    ui->plainTextEdit_DispMsg->appendPlainText("**********peer address:"+
                                               tcpsocket->peerAddress().toString());
    ui->plainTextEdit_DispMsg->appendPlainText("**********peer port:"+
                                               QString::number(tcpsocket->peerPort()));


}

void MainWindow::clientdisconnect()
{
    //客户端断开连接
    ui->plainTextEdit_DispMsg->appendPlainText("**********客户端socket断开连接**********");
    tcpsocket->deleteLater();
}

void MainWindow::socketreaddata()
{

    //读取数据
    while(tcpsocket->canReadLine())
    {
        ui->plainTextEdit_DispMsg->appendPlainText("[in]"+tcpsocket->readLine());

    }

}

//新建连接
void MainWindow::newconnection()
{
    //连接
    tcpsocket = tcpserver->nextPendingConnection();
    connect(tcpsocket,SIGNAL(connect()),this,SLOT(clientconnect()));
    clientconnect();

    //断开连接
    connect(tcpsocket,SIGNAL(disconnect()),this,SLOT(clientdisconnect()));


    //读数据
    connect(tcpsocket,SIGNAL(readyRead()),this,SLOT(socketreaddata()));

    //状态
    connect(tcpsocket,SIGNAL(stateChanged(QAbstractSocket::SocketState)),this,SLOT(OnSocketStateChanged(QAbstractSocket::SocketState)));
}

//启动服务
void MainWindow::on_pushButton_Start_clicked()
{
    //开始监听
    QString ip = ui->comboBoxIp->currentText();
    qint16 port = ui->spinBoxPort->value();

    QHostAddress address(ip);
    tcpserver->listen(address,port);

    ui->plainTextEdit_DispMsg->appendPlainText("$$$$$开始监听$$$$$$");

    ui->plainTextEdit_DispMsg->appendPlainText("$$$$$$$$$$服务器地址$$$$$$$$$$："+
                                               tcpserver->serverAddress().toString());
    ui->plainTextEdit_DispMsg->appendPlainText("$$$$$$$$$$服务器端口$$$$$$$$$$："+
                                               QString::number(tcpserver->serverPort()));

    ui->pushButton_Start->setEnabled(false);
    ui->pushButton_Stop->setEnabled(true);

}


void MainWindow::on_pushButton_Stop_clicked()
{
    if(tcpserver->isListening())
    {
        tcpserver->close();
        ui->pushButton_Start->setEnabled(true);
        ui->pushButton_Stop->setEnabled(false);
    }
}


void MainWindow::on_pushButton_Send_clicked()
{
    QString strmsg = ui->lineEdit_InputMsg->text();

    ui->plainTextEdit_DispMsg->appendPlainText("[out]"+strmsg);

    ui->lineEdit_InputMsg->clear();

    QByteArray str = strmsg.toUtf8();
    str.append("\n");
    tcpsocket->write(str);

}

void MainWindow::closeEvent(QCloseEvent *event)
{
    if(tcpserver->isListening())
    {
        tcpserver->close();
    }
    event->accept();
}


*********************************************************

二客户端

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTcpSocket> // 专门用于建立TCP连接并传输数据信息
#include <QHostAddress>
#include <QHostInfo>
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;
private:

    QTcpSocket *tcpclient;//客户端tcp套接字
    QString getlocalip();//获取本机ip地址
protected:
    void closeEvent(QCloseEvent *event);
private slots:
    void clientfunc();
    void disclientfunc();
    void socketreaddata();
    void on_pushButton_Connect_clicked();
    void on_pushButton_Disconnect_clicked();
    void on_pushButton_Send_clicked();
};
#endif // MAINWINDOW_H




**********************************************************
.c







#include "mainwindow.h"
#include "ui_mainwindow.h"

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

    tcpclient = new QTcpSocket(this);

    QString strip = getlocalip();

    ui->comboBoxIp->addItem(strip);

    connect(tcpclient,SIGNAL(connected()),this,SLOT(clientfunc()));
    connect(tcpclient,SIGNAL(disconnected()),this,SLOT(disclientfunc()));
    connect(tcpclient,SIGNAL(readyRead()),this,SLOT(socketreaddata()));



}

MainWindow::~MainWindow()
{
    delete ui;
}
//获取本机ip
QString MainWindow::getlocalip()
{
    QString hostname = QHostInfo::localHostName();
    QHostInfo hostinfo = QHostInfo::fromName(hostname);

    QString localip = "";
    QList<QHostAddress> addlist = hostinfo.addresses();

    if(!addlist.isEmpty())
    {
        for(int i = 0;i < addlist.count();i++)
        {
            QHostAddress ahost = addlist.at(i);
            if(QAbstractSocket::IPv4Protocol==ahost.protocol())
            {
                localip = ahost.toString();
                break;
            }
        }
    }
    return localip;
}

void MainWindow::closeEvent(QCloseEvent *event)
{
    if(tcpclient->state()==QAbstractSocket::ConnectedState)
    {
        tcpclient->disconnectFromHost();

    }
    event->accept();
}
void MainWindow::clientfunc()
{
    ui->plainTextEdit_DispMsg->appendPlainText("**已经连接到服务器端");

    ui->plainTextEdit_DispMsg->appendPlainText("**peer address:"+tcpclient->peerAddress().toString());

    ui->plainTextEdit_DispMsg->appendPlainText("**peer port:"+QString::number(tcpclient->peerPort()));

    ui->pushButton_Connect->setEnabled(false);
    ui->pushButton_Disconnect->setEnabled(true);


}

void MainWindow::disclientfunc()
{

    ui->plainTextEdit_DispMsg->appendPlainText("**已经断开与服务器的连接");


    ui->pushButton_Connect->setEnabled(true);
    ui->pushButton_Disconnect->setEnabled(false);

}

void MainWindow::socketreaddata()
{

    while(tcpclient->canReadLine())
    {
        ui->plainTextEdit_DispMsg->appendPlainText("[in]"+tcpclient->readLine());
    }
}


void MainWindow::on_pushButton_Connect_clicked()
{
    QString addr = ui->comboBoxIp->currentText();
    qint16 port = ui->spinBoxPort->value();
    tcpclient->connectToHost(addr,port);
}


void MainWindow::on_pushButton_Disconnect_clicked()
{
    if(tcpclient->state()==QAbstractSocket::ConnectedState)
    {
        tcpclient->disconnectFromHost();
    }

}


void MainWindow::on_pushButton_Send_clicked()
{

    QString strmsg = ui->lineEdit_InputMsg->text();
    ui->plainTextEdit_DispMsg->appendPlainText("[out]:"+strmsg);
    ui->lineEdit_InputMsg->clear();

    QByteArray str = strmsg.toUtf8();
    str.append("\n");
    tcpclient->write(str);

}