QT网络编程UDP下C/S架构广播通信(实例讲解)

2020-01-26 13:59:56

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QT有封装好的UDP协议的类，QUdpSocket，里面有我们想要的函数接口。感兴趣的话，可以看看。

先搞服务端吧，写一个子类，继承QDialog类，起名为UdpServer类。头文件要引用我们上边说的QUdpSocket这个类，还有我们想要的布局的类。

#ifndef UDPSERVER_H#define UDPSERVER_H#include <QDialog>#include <QLabel>#include <QLineEdit>#include <QPushButton>#include <QVBoxLayout>#include <QtNetwork/QUdpSocket>#include <QtNetwork/QHostAddress>#include <QTimer>class UdpServer : public QDialog{ Q_OBJECTpublic: UdpServer(QWidget *parent = 0,Qt::WindowFlags f= 0); ~UdpServer();private: QLabel * TimerLabel; QLineEdit * TextLineEdit; QPushButton* StartBtn; QVBoxLayout * mainLayout; public slots: void StartBtnClicked(); void timeout(); private: int port; bool isStarted; QUdpSocket * udpSocket; QTimer *timer;};#endif // UDPSERVER_H

在.cpp文件里，我们先是把界面显示出来，然后用udp的writedategram把想要传的写进去。

#include "udpserver.h"UdpServer::UdpServer(QWidget *parent,Qt::WindowFlags f) : QDialog(parent,f){ setWindowTitle(tr("UDP SERVER")); TimerLabel = new QLabel(tr("show time:"),this); TextLineEdit = new QLineEdit(this); StartBtn = new QPushButton(tr("start"),this); mainLayout = new QVBoxLayout(this); mainLayout-> addWidget(TimerLabel); mainLayout-> addWidget(TextLineEdit); mainLayout-> addWidget(StartBtn); connect(StartBtn,SIGNAL(clicked()),this,SLOT(StartBtnClicked())); port = 5555; isStarted = false; udpSocket = new QUdpSocket(this); timer = new QTimer(this); connect(timer,SIGNAL(timeout()),this,SLOT(timeout()));}UdpServer::~UdpServer(){}void UdpServer::StartBtnClicked(){ if(!isStarted) {  StartBtn->setText(tr("STOP"));  timer->start(1000);  isStarted = true; } else {  StartBtn->setText(tr("BEGIN"));  isStarted = false;  timer->stop(); }}void UdpServer::timeout(){ QString msg = TextLineEdit->text(); int length=0; if(msg=="") {  return; } if((length=udpSocket->writeDatagram(msg.toLatin1(),msg.length(),QHostAddress::Broadcast,port))!=msg.length()) {  qDebug() << msg.toLatin1();  return; }}

我这里用qDebug把要传的东西打印出来，进行测试，看看是否传过去了。

客户端：

#ifndef UDPCLIENT_H#define UDPCLIENT_H#include <QDialog>#include <QVBoxLayout>#include <QTextEdit>#include <QPushButton>#include <QtNetwork/QUdpSocket> class UdpClient : public QDialog{ Q_OBJECT public: UdpClient(QWidget *parent = 0); ~UdpClient(); private: QTextEdit* ReceiceTextEdit; QPushButton* CloseBtn; QVBoxLayout* mainLayout; public slots: void CloseBtnClicked(); void dataReceived(); private: int port; QUdpSocket* udpSocket;};#endif // UDPCLIENT_H

客户端很简单，怎么实现布局，我就不多说了，主要是dataReceive函数。

#include "udpclient.h"#include <QMessageBox>#include <QHostAddress>UdpClient::UdpClient(QWidget *parent) :QDialog(parent){ setWindowTitle("UDP CLIENT"); ReceiceTextEdit = new QTextEdit(this); CloseBtn = new QPushButton(tr("Close"),this); mainLayout = new QVBoxLayout(this); mainLayout->addWidget(ReceiceTextEdit); mainLayout->addWidget(CloseBtn); connect(CloseBtn,SIGNAL(clicked()),this,SLOT(CloseBtnClicked())); port =5555; udpSocket = new QUdpSocket(this); bool result = udpSocket->bind(port); if(!result) {  QMessageBox::information(this,tr("ERROR"),tr("connect error"));  return; } connect(udpSocket,SIGNAL(readyRead()),this,SLOT(dataReceived()));} UdpClient:: ~UdpClient(){}void UdpClient::CloseBtnClicked(){ close();}void UdpClient::dataReceived(){ while(udpSocket->hasPendingDatagrams()) {  QByteArray datagram;  datagram.resize(udpSocket->pendingDatagramSize());  udpSocket->readDatagram(datagram.data(),datagram.size());  QString msg=datagram.data();  ReceiceTextEdit->insertPlainText(msg); }}

最后显示一下界面，服务端发送hello。