QT 實現udp組播連接

#ifndef MAINWINDOW_H

#define MAINWINDOW_H

#include <QMainWindow>

#include <QLabel>

#include <QUdpSocket>

#include <QHostInfo>

#pragma execution_character_set("utf-8")

namespace Ui {

class MainWindow;

}

class MainWindow : public QMainWindow

{

    Q_OBJECT

public:

    explicit MainWindow(QWidget *parent = nullptr);

    ~MainWindow();

private:

    QLabel *labSocketState;

    QUdpSocket *udpsocket;

    QHostAddress groupAddress; //組播地址

    QString getLocalIP(); //獲取本機IP地址

private slots:

    void on_pushButton_clicked();

    void on_pushButton_2_clicked();

    void on_pushButton_3_clicked();

    void on_pushButton_4_clicked();

    void on_pushButton_5_clicked();

    void onSocketStateChange(QAbstractSocket::SocketState socketState);

    void onSocketReadyReady();

private:

    Ui::MainWindow *ui;

};

#endif // MAINWINDOW_H

#include "mainwindow.h"

#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :

    QMainWindow(parent),

    ui(new Ui::MainWindow)

{

    ui->setupUi(this);

    labSocketState = new QLabel("Socket 狀態");

    labSocketState->setMinimumWidth(200);

    ui->statusBar->addWidget(labSocketState);

    QString LocalIP =getLocalIP();

    this->setWindowTitle(this->windowTitle() + "----本機IP："+ LocalIP);

    udpsocket = new QUdpSocket(this);

    udpsocket->setSocketOption(QAbstractSocket::MulticastTtlOption,1);

    //將socket的QAbstractSocket::MulticastTtlOption設為1，MulticastTtlOption是UDP組播的數據包周期

    //數據包每跨一個路由會減1，缺省值為1，表示多播數據包只能在同一路由下的局域網內傳播

    connect(udpsocket,SIGNAL(stateChanged(QAbstractSocket::SocketState)),this,SLOT(onSocketStateChange(QAbstractSocket::SocketState)));

    connect(udpsocket,SIGNAL(readyRead()),this,SLOT(onSocketReadyReady()));

}

MainWindow::~MainWindow()

{

    delete ui;

}

QString MainWindow::getLocalIP()

{

    QString hostname = QHostInfo::localHostName(); //本地主機名

    //ui->plainTextEdit->appendPlainText("本地主機名："+hostname+"\n");

    QHostInfo hostinfo = QHostInfo::fromName(hostname); //本機IP

    QList<QHostAddress> addList = hostinfo.addresses();// IP地址列表

    if(!addList.isEmpty())

    {

        for(int i =0;i<addList.count();i++)

        {

            QHostAddress aHost = addList.at(i);

            return aHost.toString();

        }

    }

}

//加入組播

void MainWindow::on_pushButton_clicked()

{

    QString IP = ui->lineEdit->text();

    groupAddress = QHostAddress(IP);

    quint16 groupPort = ui->spinBox->value(); //端口

    if(udpsocket->bind(QHostAddress::AnyIPv4,groupPort,QUdpSocket::ShareAddress))

    {

        udpsocket->joinMulticastGroup(groupAddress);

        ui->plainTextEdit->appendPlainText("加入組播成功");

        ui->plainTextEdit->appendPlainText("組播地址IP："+IP);

        ui->plainTextEdit->appendPlainText("綁定端口："+QString::number(groupPort));

        ui->pushButton->setEnabled(false);

        ui->pushButton_2->setEnabled(true);

        //ui->comboBox->setEnabled(false);

    }

    else

    {

        ui->plainTextEdit->appendPlainText("綁定端口失敗");

    }

}

//退出組播

void MainWindow::on_pushButton_2_clicked()

{

    udpsocket->leaveMulticastGroup(groupAddress);//退出組播

    udpsocket->abort(); //解除綁定

    ui->pushButton->setEnabled(true);

    ui->pushButton_2->setEnabled(false);

   // ui->comboBox->setEnabled(true);

    ui->plainTextEdit->appendPlainText("已退出組播,解除端口綁定");

}

//clear

void MainWindow::on_pushButton_3_clicked()

{

    ui->plainTextEdit->clear();

}

//quit

void MainWindow::on_pushButton_4_clicked()

{

    this->close();

}

//發送

void MainWindow::on_pushButton_5_clicked()

{

    quint16 groupPort = ui->spinBox->value();

    QString msg = ui->lineEdit_2->text();

    QByteArray datagram = msg.toUtf8();

    udpsocket->writeDatagram(datagram,groupAddress,groupPort);

    ui->plainTextEdit->appendPlainText("發送組播消息"+msg);

    ui->lineEdit_2->clear();

    ui->lineEdit_2->setFocus();

}

void MainWindow::onSocketStateChange(QAbstractSocket::SocketState socketState)

{

    if(socketState==QAbstractSocket::BoundState)

    {

    }

}

void MainWindow::onSocketReadyReady()

{

    while(udpsocket->hasPendingDatagrams())

    {

        QByteArray  datagram;

        datagram.resize(udpsocket->pendingDatagramSize());

        QHostAddress peerAddr;

        quint16 peerPort;

        udpsocket->readDatagram(datagram.data(),datagram.size(),&peerAddr,&peerPort);

        QString str = datagram.data();

        QString peer = "[From"+ peerAddr.toString()+":"+ QString ::number(peerPort)+"]";

        ui->plainTextEdit->appendHtml(peer);

    }

}