1. 代码

//UdpClient.h
#ifndef UDPCLIENT_H
#define UDPCLIENT_H#include <QtNetwork>class Ex2;      // 声明类
class UdpClient : public QObject
{Q_OBJECT
public:explicit UdpClient(Ex2 *ui = nullptr);~UdpClient();void Send(QByteArray buf,QHostAddress addr, int port);void Send(char *buf,int length,QHostAddress addr, int port);void Send(char *buf,int length);void Send(QByteArray buf);void Receive();bool Close();bool Open(QString ip,int port);void SaveIpPort(QHostAddress ip,int port);
private:Ex2 *pUi;QUdpSocket *socket;QHostAddress addr;int port;
signals:};#endif // UDPCLIENT_H

//UdpClient.cpp
#include "UdpClient.h"
#include "ex2.h"
#include "ui_ex2.h"UdpClient::UdpClient(Ex2 *ui)
{socket = new QUdpSocket();pUi = ui;connect(socket,&QUdpSocket::readyRead,this,&UdpClient::Receive);
}UdpClient::~UdpClient()
{delete socket;
}bool UdpClient::Open(QString ip,int port)
{socket->close();/*取消绑定端口号使用:udpsocket->close()方法*/QHostAddress ipAddr = QHostAddress(ip);SaveIpPort(ipAddr,port);socket->bind(ipAddr,port);return true;
}bool UdpClient::Close()
{socket->close();return true;
}void UdpClient::SaveIpPort(QHostAddress ipAddr,int ipPort)
{addr = ipAddr;port = ipPort;
}void UdpClient::Send(char *buf,int length,QHostAddress addr, int port)
{QByteArray arr(buf,length);socket->writeDatagram(arr,addr,port);socket->flush();
}void UdpClient::Send(char *buf,int length)
{QByteArray arr(buf,length);socket->writeDatagram(arr,addr,port);socket->flush();
}void UdpClient::Send(QByteArray buf,QHostAddress addr, int port)
{socket->writeDatagram(buf,addr,port);socket->flush();
}void UdpClient::Send(QByteArray buf)
{socket->writeDatagram(buf,addr,port);socket->flush();
}//12 34 A1 A2 -> "12 34 A1 A2"
QString ByteArrayToHexString(QByteArray data)
{QString ret(data.toHex().toUpper());int len = ret.length()/2;for(int i=1;i<len;i++){ret.insert(2*i+i-1," ");}return ret;
}void UdpClient::Receive()
{QHostAddress addr; //用于获取发送者的 IP 和端口quint16 port;//数据缓冲区QByteArray buffer;while(socket->hasPendingDatagrams()){//调整缓冲区的大小和收到的数据大小一致buffer.resize(socket->bytesAvailable());//接收数据socket->readDatagram(buffer.data(),buffer.size(),&addr,&port);//显示QString str0 = ByteArrayToHexString(buffer) +" ";if(!buffer.isEmpty()){QString str = pUi->ui->textEditMy1->toPlainText();str += str0;//刷新显示pUi->ui->textEditMy1->setText(str);}}
}

//Ex2.cpp
#include "ex2.h"
#include "ui_ex2.h"int static cnt = 0;Ex2::Ex2(QWidget *parent): QDialog(parent), ui(new Ui::Ex2)
{
ui->setupUi(this);....//UDPudpClientSocket = new UdpClient(this);ui->lineEditUdpIp->setText("192.168.9.123");ui->lineEditUdpPort->setText("6000");
}void Ex2::on_pushButtonUdpConnect_clicked()
{if(ui->pushButtonUdpConnect->text()==tr("创建")){if(udpClientSocket->Open(ui->lineEditUdpIp->text(),ui->lineEditUdpPort->text().toInt()) == true){ui->pushButtonUdpConnect->setText("取消");}}else{udpClientSocket->Close();ui->pushButtonUdpConnect->setText("创建");}
}void Ex2::on_pushButtonUdpSend_clicked()
{//获取文本框内容并以ASCII码形式发送uchar buf[13];int i=0;buf[i++] = 0xAA;buf[i++] = 0x55;buf[i++] = 0xAA;udpClientSocket->Send((char *)buf,i);
}

//Ex2.h
#ifndef EX2_H
#define EX2_H#include <QDialog>#include <QtSerialPort/QSerialPort>
#include <QtSerialPort/QSerialPortInfo>
#include ".\UDP\UdpClient.h"QT_BEGIN_NAMESPACE
namespace Ui { class Ex2; }
QT_END_NAMESPACEclass Ex2 : public QDialog
{Q_OBJECTpublic:Ex2(QWidget *parent = nullptr);~Ex2();Ui::Ex2 *ui;UdpClient *udpClientSocket;private slots:void on_pushButtonUdpConnect_clicked();void on_pushButtonUdpSend_clicked();private://Ui::Ex2 *ui;QSerialPort *serial;
};
#endif // EX2_H

2. 效果

以上代码可以实现UDP收发功能。