[QT]QT教程之实例分析[九] 网络广播程序(QUdpSocket)

重点知识已近在代码里注释...

请仔细看代码

本文原创

转载请保留此链接 http://blog.csdn.net/siren0203
本章内容 以一个完整的 广播程序为实例 再次详细说明 UDP协议的使用方法..

发送端...

头文件

udpSocket.h

#ifndef UPDSOCKET_H
#define UPDSOCKET_H
#include <QDialog>
class QUdpSocket;
class QTextEdit;
class QVBoxLayout;
class Server:public QDialog{
Q_OBJECT
public:
Server(QWidget *parent=0);
QPushButton *send;
QUdpSocket *udpSocket;
QTextEdit *textEdit;
QVBoxLayout *layout;
int port;
private slots:
void submit();
};
#endif // UPDSOCKET_H

实现代码

main.cpp

#include <QApplication>
#include <QUdpSocket>
#include <QTextEdit>
#include <QVBoxLayout>
#include <QPushButton>
#include <QMessageBox>
#include <QTextCodec>
#include "updSocket.h"
Server::Server(QWidget *parent):QDialog(parent){
port=4444;
//创建 QUdpSocket 对象
udpSocket=new QUdpSocket(this);
textEdit=new QTextEdit();
send=new QPushButton(tr("发送"));
layout=new QVBoxLayout;
layout->addWidget(textEdit);
layout->addWidget(send);
setLayout(layout);
//关联 发送 信号到槽
connect(send,SIGNAL(clicked()),this,SLOT(submit()));
setWindowTitle(tr("服务器端"));
}
void Server::submit(){
QMessageBox box;
QString text=textEdit->toPlainText();
if(text.length()==0){
box.setText(tr("请输入发送内容"));
}
/*开始发送数据*/
//初始化长度
int len=0;
//udpSocket->writeDatagram(发送的数据,发送数据的长度,IP,端口); 返回一个长度.
len=udpSocket->writeDatagram(text.toLatin1(),text.length(),QHostAddress::LocalHost,port);
if(len){
box.setText(tr("发送成功"));
}
box.exec();
}
int main(int argc,char ** argv){
QApplication app(argc,argv);
QTextCodec ::setCodecForTr(QTextCodec::codecForName("gb2312"));
Server server;
server.show();
return app.exec();
}

---------------下面是接收端也就是客户端----------------------------------

头文件

Client.h

#ifndef SERVER_H
#define SERVER_H
#include <QDialog>
class QUdpSocket;
class QPushButton;
class QVBoxLayout;
class QTextEdit;
class Client :public QDialog{
Q_OBJECT
public:
Client(QWidget *parent=0);
QPushButton *close;
QUdpSocket *udpSocket;
QVBoxLayout *layout;
QTextEdit *textEdit;
int port;
private slots:
void clientMessage();
};
#endif // SERVER_H

实现代码

main.cpp

#include <QApplication>
#include <QPushButton>
#include <QVBoxLayout>
#include <QUdpSocket>
#include <QTextEdit>
#include <QTextCodec>
#include <QMessageBox>
#include "Client.h"
Client::Client(QWidget *parent):QDialog(parent){
port=4444;
close=new QPushButton(this);
textEdit=new QTextEdit(this);
close->setText(tr("关闭"));
layout=new QVBoxLayout(this);
layout->addWidget(close);
layout->addWidget(textEdit);
setLayout(layout);
setWindowTitle(tr("接收端"));
//实例化QUdpSocket 对象...
udpSocket=new QUdpSocket(this);
//监听端口
bool conn=udpSocket->bind(port);
//链接失败
if(!conn){
QMessageBox box;
box.setText(tr("链接错误"));
box.exec();
}else{
//把udpSocket的信号关联到槽
connect(udpSocket,SIGNAL(readyRead()),this,SLOT(clientMessage()));
}
}
void Client::clientMessage(){
while(udpSocket->hasPendingDatagrams()){    //是否读到数据
QByteArray data;
//udpSocket->pendingDatagramSize 获取报文长度
//data.resize 给 data 数组设置长度
data.resize(udpSocket->pendingDatagramSize());
//读入数据
udpSocket->readDatagram(data.data(),data.size());
//显示数据内容
QString str=data.data();
textEdit->insertPlainText(str+"/r/n");
}
}
int main(int argc,char ** argv){
QApplication app(argc,argv);
QTextCodec::setCodecForTr(QTextCodec::codecForName("gb2312"));
Client client;
client.show();
return app.exec();
}

-------------------------下面是 演示图片-------------------