Qt development - Network Programming UDP Client

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table of Contents

Renderings

Manual Readings

bind binding:

readRead()：

Routine

udpclient.h

udpclient.cpp

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Renderings

And an upper end service in conjunction with the transceiver

Manual Readings

bind binding:

For UDP nested keywords, after binding, whenever a UDP data table reaches the specified address or designated port, readRead () signal will be transmitted!

readRead()：

Each time new data is read from the current read channel device, this signal will be issued. It is sent only when new data is available again, for example when a new payload network data arrives at the network sockets, or when a new block of data when attached to the device.

This signal can not be recursive transmit (what signals can transmit a recursive ??)

Note If you re-enter the event loop or call waitForReadyRead () in a tank connected to readyRead () signal, the signal will not be re-issued (although waitForReadyRead () may still return true).

If you re-enter the event loop in a tank connected to readyRead () signal or call waitForReadyRead (), the signal will not be re-issued (although waitForReadyRead () may still return true).

Routine

udpclient.h

#ifndef UDPCLIENT_H
#define UDPCLIENT_H

#include <QDialog>
#include <QVBoxLayout>
#include <QTextEdit>
#include <QPushButton>
#include <QUdpSocket>
#include <QMessageBox>
#include <QHostAddress>

class UDPClient : public QDialog
{
    Q_OBJECT

public:
    UDPClient(QWidget *parent = nullptr);
    ~UDPClient();

public slots:
    void CloseBtnClicked();
    void dataRecieved();

private:
    //布局控件
    QTextEdit *ReciveTextEdit;
    QPushButton *CloseBtn;
    QVBoxLayout *mainLayout;
    //网络控件
    int port;
    QUdpSocket *udpSocket;

};

#endif // UDPCLIENT_H

udpclient.cpp

#include "udpclient.h"

UDPClient::UDPClient(QWidget *parent)
    : QDialog(parent)
{
    setWindowIcon(QIcon("icon.png"));
    setWindowTitle(QStringLiteral("UDP客户端"));
    //布局设计
    ReciveTextEdit = new QTextEdit(this);
    CloseBtn = new QPushButton(this);
    CloseBtn->setText(QStringLiteral("关闭"));
    mainLayout = new QVBoxLayout(this);
    mainLayout->addWidget(ReciveTextEdit);
    mainLayout->addWidget(CloseBtn);
    //关闭事件关联
    connect(CloseBtn,SIGNAL(clicked()),this,SLOT(CloseBtnClicked()));
    //网络参数设定,UDP端口参数设定
    quint16 port = 5555;
    udpSocket = new QUdpSocket(this);
    //数据事件关联
    connect(udpSocket,SIGNAL(readRead()),this,SLOT(dataRecived()));
    bool result = udpSocket->bind(port);//绑定到指定的端口上
    if(!result){//如果错误返回
        QMessageBox::information(this,QStringLiteral("错误！"),QStringLiteral("UDP出现了错误!"));
        return;
    }
    
}

UDPClient::~UDPClient()
{

}

//关闭按键事件
void UDPClient::CloseBtnClicked(){
    close();
}

void UDPClient::dataRecieved(){
    while (udpSocket->hasPendingDatagrams()) {//判断数据报表是否有效
        QByteArray datagram;
        datagram.resize(udpSocket->pendingDatagramSize());
        udpSocket->readDatagram(datagram.data(),datagram.size());
        QString msg = datagram.data();
        ReciveTextEdit->insertPlainText(msg);//写入返回的数据
    }
    
    
}