72-UDP协议工作原理及实战

#ifndef UDPCOMM_H
#define UDPCOMM_H#include <QMainWindow>
#include <QUdpSocket> // 用于发送和接收UDP数据报
#include <QtNetwork>QT_BEGIN_NAMESPACE
namespace Ui { class udpComm; }
QT_END_NAMESPACEclass udpComm : public QMainWindow
{Q_OBJECTpublic:udpComm(QWidget *parent = nullptr);~udpComm();private slots:void on_pushButton_start_clicked();void on_pushButton_stop_clicked();void on_pushButton_sengmsg_clicked();void on_pushButton_broadastmsg_clicked();private:Ui::udpComm *ui;// 自定义函数获取本机的IP地址
public:QUdpSocket *udpsocket;QString GetLocalIpAddress(); // 获取本机IP地址// 自己定义槽
private slots:void  SocketReadyReadData(); // 读取socket传输数据信息
};
#endif // UDPCOMM_H//.c#include "udpcomm.h"
#include "ui_udpcomm.h"
#include <QMessageBox>udpComm::udpComm(QWidget *parent): QMainWindow(parent), ui(new Ui::udpComm)
{ui->setupUi(this);QString strip=GetLocalIpAddress(); // 调用此函数返回对应本机IP地址QMessageBox::information(this,"结果",strip,QMessageBox::Yes);ui->comboBoxtargetip->addItem(strip); // 将IP地址显示到comboBox控件udpsocket=new QUdpSocket(this);connect(udpsocket,SIGNAL(readyRead()),this,SLOT(SocketReadyReadData()));}udpComm::~udpComm()
{delete ui;
}void udpComm::on_pushButton_start_clicked()
{quint16 port=ui->spinBoxbindport->value(); // 本机UDP端口if(udpsocket->bind(port)){ui->plainTextEditdispmsg->appendPlainText("**********绑定成功**********");ui->plainTextEditdispmsg->appendPlainText("$$$$$$$$$$绑定端口$$$$$$$$$$："+QString::number(udpsocket->localPort()));ui->pushButton_start->setEnabled(false);ui->pushButton_stop->setEnabled(true);}else{ui->plainTextEditdispmsg->appendPlainText("**********绑定失败**********");}
}void udpComm::on_pushButton_stop_clicked()
{udpsocket->abort();ui->pushButton_start->setEnabled(true);ui->pushButton_stop->setEnabled(false);ui->plainTextEditdispmsg->appendPlainText("**********已经停止服务**********");}void udpComm::on_pushButton_sengmsg_clicked()
{QString targetIpAddress=ui->comboBoxtargetip->currentText(); // 获取目标IP地址QHostAddress targetaddress(targetIpAddress);quint16 targetport=ui->spinBoxtargetport->value(); // 获取端口QString strmsg=ui->lineEditmsg->text(); // 获取发送消息内容QByteArray str=strmsg.toUtf8();udpsocket->writeDatagram(str,targetaddress,targetport); // 发送数据报信息ui->plainTextEditdispmsg->appendPlainText("[out]："+str);ui->lineEditmsg->clear(); // 清除编辑框控件内容ui->lineEditmsg->setFocus(); // 将光标焦点定位到编辑框控件}void udpComm::on_pushButton_broadastmsg_clicked()
{quint16 targetport=ui->spinBoxtargetport->value(); // 获取端口QString strmsg=ui->lineEditmsg->text(); // 获取发送消息内容QByteArray str=strmsg.toUtf8();udpsocket->writeDatagram(str,QHostAddress::Broadcast,targetport); // 发送数据报信息ui->plainTextEditdispmsg->appendPlainText("[broadcast]："+str);ui->lineEditmsg->clear(); // 清除编辑框控件内容ui->lineEditmsg->setFocus(); // 将光标焦点定位到编辑框控件
}QString udpComm::GetLocalIpAddress()
{// 根据主机名称，获取IP地址QString strHostName=QHostInfo::localHostName();QHostInfo hostinfo=QHostInfo::fromName(strHostName); //  通过主机名称获取IP地址QString strLocalIp="";QList<QHostAddress> addresslist=hostinfo.addresses(); // IP地址列表if(!addresslist.isEmpty()){for(int i=0;i<addresslist.count();i++){QHostAddress hostaddr=addresslist.at(i);if(QAbstractSocket::IPv4Protocol==hostaddr.protocol()){strLocalIp=hostaddr.toString();break;}}}return strLocalIp;
}void udpComm::SocketReadyReadData()
{// 读取接收到的数据报信息// 用此函数返回true至少有一个数据报需要读取while(udpsocket->hasPendingDatagrams()){QByteArray datagrams;datagrams.resize(udpsocket->pendingDatagramSize());QHostAddress paddress;quint16 pport;// 通过readDatagram()此函数读取数据报，udpsocket->readDatagram(datagrams.data(),datagrams.size(),&paddress,&pport);QString strs=datagrams.data();QString peer="[From:"+paddress.toString()+":"+QString::number(pport)+"]:";ui->plainTextEditdispmsg->appendPlainText(peer+strs);}
}