Qt中QUdpSocket类的简单使用详解

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QUdpSocket>
QT_BEGIN_NAMESPACE
namespace Ui {
class MainWindow;
}
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
private slots:
    void on_btnUnicast_clicked();
    void on_btnBoardcast_clicked();
private:
    Ui::MainWindow *ui;
    QUdpSocket* m_pSender = nullptr;
};
#endif // MAINWINDOW_H

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QHostAddress>
#include <QDebug>
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    m_pSender = new QUdpSocket(this);
}
MainWindow::~MainWindow()
{
    delete ui;
    delete m_pSender;
}
void MainWindow::on_btnUnicast_clicked()
{
    QString strText = ui->lineEdit->text();
    if(strText.isEmpty())
        return;
    QHostAddress host("127.0.0.1");
    quint16 nPort = 8888;
    qint64 nSend = m_pSender->writeDatagram(strText.toUtf8(),host,nPort);
    if(nSend == -1)
    {
        qDebug() << "单播发送失败" << m_pSender->errorString();
    }
    else
    {
        qDebug() << "单播发送成功，字节数" << nSend;
    }
}
void MainWindow::on_btnBoardcast_clicked()
{
    QString strText = ui->lineEdit->text();
    if(strText.isEmpty())
        return;
    quint16 nPort = 8888;
    qint64 nSend = m_pSender->writeDatagram(strText.toUtf8(),QHostAddress::Broadcast,nPort);
    if(nSend == -1)
    {
        qDebug() << "广播发送失败" << m_pSender->errorString();
    }
    else
    {
        qDebug() << "广播发送成功，字节数" << nSend;
    }
}

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QUdpSocket>
QT_BEGIN_NAMESPACE
namespace Ui {
class MainWindow;
}
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();
public slots:
    void ReadDatagram();
private:
    Ui::MainWindow *ui;
    QUdpSocket* m_pReceiver;
};
#endif // MAINWINDOW_H

#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    m_pReceiver = new QUdpSocket(this);
    quint16 listenPort = 8888;
    // 绑定端口：QHostAddress::Any 表示监听所有网卡的该端口（支持本机/局域网/外网）
    bool bBind = m_pReceiver->bind(QHostAddress::Any,listenPort);
    if(!bBind)
    {
        ui->textEdit->append("绑定端口失败：" + m_pReceiver->errorString());
    }
    else
    {
        ui->textEdit->append("已绑定端口 " + QString::number(listenPort) + "，等待接收数据...");
    }
    // 绑定接收数据信号：当有数据到达时触发readyRead()
    connect(m_pReceiver,&QUdpSocket::readyRead,this,&MainWindow::ReadDatagram);
}
MainWindow::~MainWindow()
{
    delete ui;
    delete m_pReceiver;
}
void MainWindow::ReadDatagram()
{
    // 循环读取所有待处理的数据包（可能同时有多个）
    while (m_pReceiver->hasPendingDatagrams())
    {
        QByteArray datagram;
        // 预留足够的缓冲区（根据数据包大小调整，这里设为1024）
        datagram.resize(m_pReceiver->pendingDatagramSize());
        QHostAddress senderIp; // 发送方IP
        quint16 senderPort;    // 发送方端口
        // 读取数据包，同时获取发送方的IP和端口
        qint64 readBytes = m_pReceiver->readDatagram(
            datagram.data(),
            datagram.size(),
            &senderIp,
            &senderPort
            );
        if (readBytes == -1)
        {
            ui->textEdit->append("接收失败：" + m_pReceiver->errorString());
            continue;
        }
        // 解析并显示数据
        QString recvData = QString::fromUtf8(datagram);
        QString log = QString("[%1:%2] 接收数据：%3")
                          .arg(senderIp.toString())
                          .arg(senderPort)
                          .arg(recvData);
        ui->textEdit->append(log);
    }
}