Qt学习笔记-服务器端获取UDP封包源IP地址

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简介

源码

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简介

本篇博文修改于：

Qt文档阅读笔记-QUdpSocket基本表述及简单实现

https://blog.csdn.net/qq78442761/article/details/85258574

原理请看上面的博文

获取源IP地址的原理：

在槽函数中进行获取，记住这种逻辑，很重要，因为Socket里面有个函数叫peerAddr这个不会获取任何东西！

关键源码如下：

 QHostAddress srcAddress;         quint16 nSrcPort;         QByteArray datagram;         datagram.resize(m_udpSocket->pendingDatagramSize());         m_udpSocket->readDatagram(datagram.data(), datagram.size(), &srcAddress, &nSrcPort);;

程序运行截图如下：

源码

widget.h

 #ifndef WIDGET_H #define WIDGET_H  #include <QWidget>  QT_BEGIN_NAMESPACE class QUdpSocket; QT_END_NAMESPACE  namespace Ui { class Widget; }  class Widget : public QWidget {     Q_OBJECT  public:     explicit Widget(QWidget *parent = 0);     ~Widget();  protected slots:     void readPendingDatagrams();  private:     Ui::Widget *ui;     QUdpSocket *m_udpSocket; };  #endif // WIDGET_H 

main.cpp

 #include "widget.h" #include <QApplication>  int main(int argc, char *argv[]) {     QApplication a(argc, argv);     Widget w;     w.show();      return a.exec(); } 

widget.cpp

 #include "widget.h" #include "ui_widget.h" #include <QUdpSocket> #include <QNetworkDatagram> #include <QHostAddress> #include <QDebug>  Widget::Widget(QWidget *parent) :     QWidget(parent),     ui(new Ui::Widget) {     ui->setupUi(this);     this->setWindowTitle("接收端");      m_udpSocket = new QUdpSocket(this);      if(!m_udpSocket->bind(7755)){           qDebug() << "bind failed! The assert will be triggred!";         Q_ASSERT(!"bind faile!");     }      connect(m_udpSocket, SIGNAL(readyRead()), this, SLOT(readPendingDatagrams())); }  Widget::~Widget() {     delete ui; }  void Widget::readPendingDatagrams() {     qDebug() << "readPendingDatagrams called!";     while(m_udpSocket->hasPendingDatagrams()){          QHostAddress srcAddress;         quint16 nSrcPort;         QByteArray datagram;         datagram.resize(m_udpSocket->pendingDatagramSize());         m_udpSocket->readDatagram(datagram.data(), datagram.size(), &srcAddress, &nSrcPort);;         QString firstData = srcAddress.toString() + " " + QString::number(nSrcPort) + " :";         ui->textEdit->append(firstData + datagram);     } }

文章来源: Qt学习笔记-服务器端获取UDP封包源IP地址