十四、Qt主机信息与网络编程

一、主机信息

1、主机信息接口

• QHostInfo：获取主机名称和IP地址
• QNetWorkInterface：获取主���的所有网络接口，包括子网掩码和广播地址等

  （1）使用

  项目添加模块

  QT       += network

  2、实现程序

  （1）创建项目，基于QDialog

  （2）实现功能

  #ifndef DIALOG_H#define DIALOG_H#include #include #include namespace Ui{class Dialog;}class Dialog : public QDialog{    Q_OBJECTprivate:    QString protocolName(QAbstractSocket::NetworkLayerProtocol protocol);public:    explicit Dialog(QWidget *parent = nullptr);    ~Dialog();private slots:    void on_btnHostIP_clicked();    void on_btnClearText_clicked();    void on_btnDnsIP_clicked();    void on_lookUpHostInfo(QHostInfo host);    void on_btnAllAddresses_clicked();    void on_btnAllInterface_clicked();private:    Ui::Dialog *ui;};#endif // DIALOG_H

  #include "dialog.h"#include "ui_dialog.h"QString Dialog::protocolName(QAbstractSocket::NetworkLayerProtocol protocol){    switch (protocol)    {    case QAbstractSocket::IPv4Protocol:        return "IPv4 Protocol";        break;    case QAbstractSocket::IPv6Protocol:        return "IPv6 Protocol";        break;    case QAbstractSocket::AnyIPProtocol:        return "AnyIP Protocol";        break;    default:        return "Unknown Protocol";        break;    }}Dialog::Dialog(QWidget *parent) :    QDialog(parent),    ui(new Ui::Dialog){    ui->setupUi(this);}Dialog::~Dialog(){    delete ui;}void Dialog::on_btnHostIP_clicked(){    QString hostName = QHostInfo::localHostName();    ui->plainTextEdit->appendPlainText(hostName);    QHostInfo hostInfo = QHostInfo::fromName(hostName);    QList addList = hostInfo.addresses();    foreach (auto aHost, addList)    {        if(ui->checkBox->isChecked())        {            if(aHost.protocol() == QAbstractSocket::IPv4Protocol)            {                ui->plainTextEdit->appendPlainText("协议：" + protocolName(aHost.protocol()));                ui->plainTextEdit->appendPlainText("本机IP地址：" + aHost.toString());                ui->plainTextEdit->appendPlainText("");            }        }        else        {            ui->plainTextEdit->appendPlainText("协议：" + protocolName(aHost.protocol()));            ui->plainTextEdit->appendPlainText("本机IP地址：" + aHost.toString());            ui->plainTextEdit->appendPlainText("");        }    }}void Dialog::on_btnClearText_clicked(){    ui->plainTextEdit->clear();}void Dialog::on_btnDnsIP_clicked(){    // 异步方式    QString hostName = ui->lineEdit->text();    ui->plainTextEdit->appendPlainText("正在查询主机信息：" + hostName);    QHostInfo::lookupHost(hostName, this, SLOT(on_lookUpHostInfo(QHostInfo)));}void Dialog::on_lookUpHostInfo(QHostInfo host){    QList addList = host.addresses();    foreach (auto aHost, addList)    {        if(ui->checkBox->isChecked())        {            if(aHost.protocol() == QAbstractSocket::IPv4Protocol)            {                ui->plainTextEdit->appendPlainText("协议：" + protocolName(aHost.protocol()));                ui->plainTextEdit->appendPlainText("IP地址：" + aHost.toString());                ui->plainTextEdit->appendPlainText("");            }        }        else        {            ui->plainTextEdit->appendPlainText("协议：" + protocolName(aHost.protocol()));            ui->plainTextEdit->appendPlainText("IP地址：" + aHost.toString());            ui->plainTextEdit->appendPlainText("");        }    }}void Dialog::on_btnAllAddresses_clicked(){    QList addList = QNetworkInterface::allAddresses();    foreach (auto aHost, addList)    {        if(ui->checkBox->isChecked())        {            if(aHost.protocol() == QAbstractSocket::IPv4Protocol)            {                ui->plainTextEdit->appendPlainText("协议：" + protocolName(aHost.protocol()));                ui->plainTextEdit->appendPlainText("IP地址：" + aHost.toString());                ui->plainTextEdit->appendPlainText("");            }        }        else        {            ui->plainTextEdit->appendPlainText("协议：" + protocolName(aHost.protocol()));            ui->plainTextEdit->appendPlainText("IP地址：" + aHost.toString());            ui->plainTextEdit->appendPlainText("");        }    }}void Dialog::on_btnAllInterface_clicked(){    QList list = QNetworkInterface::allInterfaces();    foreach (auto aInterface, list)    {        if(!aInterface.isValid())        {            continue;        }        ui->plainTextEdit->appendPlainText("设备名称: " + aInterface.humanReadableName());        ui->plainTextEdit->appendPlainText("硬件地址: " + aInterface.hardwareAddress());        QList entryList = aInterface.addressEntries();        foreach (auto aEntry, entryList)        {            ui->plainTextEdit->appendPlainText("  IP地址: " + aEntry.ip().toString());            ui->plainTextEdit->appendPlainText("  子网掩码: " + aEntry.netmask().toString());            ui->plainTextEdit->appendPlainText("  广播地址: " + aEntry.broadcast().toString());        }        ui->plainTextEdit->appendPlainText("");    }}

  二、TCP通信

  TCP是一种被大多数Internet网络协议（HTTP、FTP等）用于数据传输的低级网络协议，是可靠的、面向流、面向连接的传输协议。

  1、相关类

  （1）继承关系

  QIODeviceQAbstractSocketQTcpSocketQSctpSocketQSslSocket // 加密QUdpSocket

  2、实现服务端程序

  （1）创建项目

  （2）添加图标资源

  （3）实现服务器功能

  #ifndef MAINWINDOW_H#define MAINWINDOW_H#include #include #include #include namespace Ui{class MainWindow;}class MainWindow : public QMainWindow{    Q_OBJECTprivate:    QLabel *labListen;    QLabel *labSocketState;    QTcpServer *tcpServer;    QTcpSocket *tcpSocket;public:    explicit MainWindow(QWidget *parent = nullptr);    ~MainWindow();protected:    void closeEvent(QCloseEvent *event);private:    QString getLocalIP();private slots:    void on_newConnection();    void on_clientConnected();    void on_clientDisconnected();    void on_clientStateChanged(QAbstractSocket::SocketState state);    void on_clientReadyRead();    void on_actStartListen_triggered();    void on_actStopListen_triggered();    void on_actClearText_triggered();    void on_btnSend_clicked();private:    Ui::MainWindow *ui;};#endif // MAINWINDOW_H

  #include "mainwindow.h"#include "ui_mainwindow.h"#include MainWindow::MainWindow(QWidget *parent) :    QMainWindow(parent),    ui(new Ui::MainWindow){    ui->setupUi(this);    labListen = new QLabel("监听状态：");    labListen->setMinimumWidth(200);    labSocketState = new QLabel("Socket状态：");    labSocketState->setMinimumWidth(200);    ui->statusBar->addWidget(labListen);    ui->statusBar->addWidget(labSocketState);    setWindowTitle("服务器：" + getLocalIP());    tcpServer = new QTcpServer(this);    connect(tcpServer, SIGNAL(newConnection()),            this, SLOT(on_newConnection()));}MainWindow::~MainWindow(){    delete ui;}void MainWindow::closeEvent(QCloseEvent *event){    if(tcpServer->isListening())    {        tcpServer->close();    }    event->accept();}QString MainWindow::getLocalIP(){    QString hostName = QHostInfo::localHostName();    QHostInfo hostInfo = QHostInfo::fromName(hostName);    QString loaclIP;    QList addList = hostInfo.addresses();    foreach (auto aHost, addList)    {        if(aHost.protocol() == QAbstractSocket::IPv4Protocol)        {            if(loaclIP.isEmpty())            {                loaclIP = aHost.toString();            }            ui->comboBoxAddresses->addItem(aHost.toString());        }    }    return loaclIP;}void MainWindow::on_newConnection(){    tcpSocket = tcpServer->nextPendingConnection(); //获取socket    connect(tcpSocket, SIGNAL(connected()), this, SLOT(on_clientConnected()));    on_clientConnected(); //当前状态已经发送，需要直接调用通知    connect(tcpSocket, SIGNAL(disconnected()), this, SLOT(on_clientDisconnected()));    connect(tcpSocket, SIGNAL(stateChanged(QAbstractSocket::SocketState)),            this, SLOT(on_clientStateChanged(QAbstractSocket::SocketState)));    on_clientStateChanged(tcpSocket->state()); //当前状态已经发送，需要直接调用通知    connect(tcpSocket, SIGNAL(readyRead()), this, SLOT(on_clientReadyRead()));}void MainWindow::on_clientConnected(){    ui->plainTextEdit->appendPlainText("**client socket connected");    ui->plainTextEdit->appendPlainText("**peer address: " + tcpSocket->peerAddress().toString());    ui->plainTextEdit->appendPlainText("**peer port " + QString::number(tcpSocket->peerPort()));}void MainWindow::on_clientDisconnected(){    ui->plainTextEdit->appendPlainText("**client socket disconnected");    tcpSocket->deleteLater();}void MainWindow::on_clientStateChanged(QAbstractSocket::SocketState state){    switch (state)    {    case QAbstractSocket::UnconnectedState:        labSocketState->setText("socket状态：UnconnectedState");        break;    case QAbstractSocket::HostLookupState:        labSocketState->setText("socket状态：HostLookupState");        break;    case QAbstractSocket::ConnectingState:        labSocketState->setText("socket状态：ConnectingState");        break;    case QAbstractSocket::ConnectedState:        labSocketState->setText("socket状态：ConnectedState");        break;    case QAbstractSocket::BoundState:        labSocketState->setText("socket状态：BoundState");        break;    case QAbstractSocket::ListeningState:        labSocketState->setText("socket状态：ListeningState");        break;    case QAbstractSocket::ClosingState:        labSocketState->setText("socket状态：ClosingState");        break;    default:        break;    }}void MainWindow::on_clientReadyRead(){    //    while(tcpSocket->canReadLine())    int nLen = 0;    do    {        char data[1024] = {0};        nLen = tcpSocket->readLine(data, 1023);        if(nLen > 0)        {            ui->plainTextEdit->appendPlainText(QString::asprintf("[in]: %s", data));        }    } while(nLen > 0);}void MainWindow::on_actStartListen_triggered(){    QString IP = ui->comboBoxAddresses->currentText();    int port = ui->spinBoxPort->value();    QHostAddress addr(IP);    tcpServer->listen(addr, port);    ui->plainTextEdit->appendPlainText("**开始监听");    ui->plainTextEdit->appendPlainText("**服务IP：" + tcpServer->serverAddress().toString());    ui->plainTextEdit->appendPlainText("**服务器端口：" + QString::number(tcpServer->serverPort()));    ui->actStartListen->setEnabled(false);    ui->actStopListen->setEnabled(true);    labListen->setText("监听状态：开始");}void MainWindow::on_actStopListen_triggered(){    if(tcpServer->isListening())    {        tcpServer->close();        ui->actStartListen->setEnabled(true);        ui->actStopListen->setEnabled(false);        labListen->setText("监听状态：停止");    }}void MainWindow::on_actClearText_triggered(){    ui->plainTextEdit->clear();}void MainWindow::on_btnSend_clicked(){    QString msg = ui->lineEdit->text();    ui->plainTextEdit->appendPlainText("[out] " + msg);    ui->lineEdit->clear();    ui->lineEdit->setFocus();    msg += "\n";    QByteArray data = msg.toUtf8();    tcpSocket->write(data);}

  3、实现客户端程序

  （1）创建项目

  （2）添加图标资源

  （3）实现功能

  #ifndef MAINWINDOW_H#define MAINWINDOW_H#include #include #include #include namespace Ui{class MainWindow;}class MainWindow : public QMainWindow{    Q_OBJECTprivate:    QLabel *labSocketState;    QTcpSocket *tcpSocket;public:    explicit MainWindow(QWidget *parent = nullptr);    ~MainWindow();private:    QString getLocalIP();private slots:    void on_Connected();    void on_Disconnected();    void on_StateChanged(QAbstractSocket::SocketState state);    void on_ReadyRead();    void on_btnSend_clicked();    void on_actConnect_triggered();    void on_actDisconnect_triggered();    void on_actClear_triggered();private:    Ui::MainWindow *ui;};#endif // MAINWINDOW_H

  #include "mainwindow.h"#include "ui_mainwindow.h"#include MainWindow::MainWindow(QWidget *parent) :    QMainWindow(parent),    ui(new Ui::MainWindow){    ui->setupUi(this);    labSocketState = new QLabel("Socket状态：");    labSocketState->setMinimumWidth(200);    ui->statusBar->addWidget(labSocketState);    setWindowTitle("客户端：" + getLocalIP());    tcpSocket = new QTcpSocket;    connect(tcpSocket, SIGNAL(connected()), this, SLOT(on_Connected()));    connect(tcpSocket, SIGNAL(disconnected()), this, SLOT(on_Disconnected()));    connect(tcpSocket, SIGNAL(stateChanged(QAbstractSocket::SocketState)),            this, SLOT(on_StateChanged(QAbstractSocket::SocketState)));    connect(tcpSocket, SIGNAL(readyRead()), this, SLOT(on_ReadyRead()));}MainWindow::~MainWindow(){    delete ui;}QString MainWindow::getLocalIP(){    QString hostName = QHostInfo::localHostName();    QHostInfo hostInfo = QHostInfo::fromName(hostName);    QString loaclIP;    QList addList = hostInfo.addresses();    foreach (auto aHost, addList)    {        if(aHost.protocol() == QAbstractSocket::IPv4Protocol)        {            if(loaclIP.isEmpty())            {                loaclIP = aHost.toString();            }            ui->comboBox->addItem(aHost.toString());        }    }    return loaclIP;}void MainWindow::on_Connected(){    ui->plainTextEdit->appendPlainText("**socket connected");    ui->plainTextEdit->appendPlainText("**peer address: " + tcpSocket->peerAddress().toString());    ui->plainTextEdit->appendPlainText("**peer port " + QString::number(tcpSocket->peerPort()));}void MainWindow::on_Disconnected(){    ui->plainTextEdit->appendPlainText("**socket disconnected");}void MainWindow::on_StateChanged(QAbstractSocket::SocketState state){    switch (state)    {    case QAbstractSocket::UnconnectedState:        labSocketState->setText("socket状态：UnconnectedState");        break;    case QAbstractSocket::HostLookupState:        labSocketState->setText("socket状态：HostLookupState");        break;    case QAbstractSocket::ConnectingState:        labSocketState->setText("socket状态：ConnectingState");        break;    case QAbstractSocket::ConnectedState:        labSocketState->setText("socket状态：ConnectedState");        break;    case QAbstractSocket::BoundState:        labSocketState->setText("socket状态：BoundState");        break;    case QAbstractSocket::ListeningState:        labSocketState->setText("socket状态：ListeningState");        break;    case QAbstractSocket::ClosingState:        labSocketState->setText("socket状态：ClosingState");        break;    default:        break;    }}void MainWindow::on_ReadyRead(){    int nLen = 0;    do    {        char data[1024] = {0};        nLen = tcpSocket->readLine(data, 1023);        if(nLen > 0)        {            ui->plainTextEdit->appendPlainText(QString::asprintf("[in]: %s", data));        }    } while(nLen > 0);}void MainWindow::on_btnSend_clicked(){    QString msg = ui->lineEdit->text();    ui->plainTextEdit->appendPlainText("[out] " + msg);    ui->lineEdit->clear();    ui->lineEdit->setFocus();    msg += "\n";    QByteArray data = msg.toUtf8();    tcpSocket->write(data);}void MainWindow::on_actConnect_triggered(){    QString IP = ui->comboBox->currentText();    int port = ui->spinBox->value();    tcpSocket->connectToHost(IP, port);    ui->actConnect->setEnabled(false);    ui->actDisconnect->setEnabled(true);}void MainWindow::on_actDisconnect_triggered(){    if(tcpSocket->state() == QAbstractSocket::ConnectedState)    {        tcpSocket->disconnectFromHost();    }    ui->actConnect->setEnabled(true);    ui->actDisconnect->setEnabled(false);}void MainWindow::on_actClear_triggered(){    ui->plainTextEdit->clear();}

  三、UDP通信

  UDP用户数据报协议，是轻量的、不可靠的、面向数据报、无连接的协议。

  1、实现单播/广播程序

  （1）创建项目

  （2）添加图标资源

  （3）实现功能

  #include "mainwindow.h"#include "ui_mainwindow.h"#include MainWindow::MainWindow(QWidget *parent) :    QMainWindow(parent),    ui(new Ui::MainWindow){    ui->setupUi(this);    labSocketState = new QLabel("Socket状态：");    labSocketState->setMinimumWidth(200);    ui->statusBar->addWidget(labSocketState);    QString localIP = getLocalIP();    setWindowTitle("Udp收发器:" + localIP);    udpSocket = new QUdpSocket(this);    connect(udpSocket, SIGNAL(stateChanged(QAbstractSocket::SocketState)),            this, SLOT(on_StateChanged(QAbstractSocket::SocketState)));    connect(udpSocket, SIGNAL(readyRead()),            this, SLOT(on_SocketReadyRead()));}MainWindow::~MainWindow(){    delete ui;}QString MainWindow::getLocalIP(){    QString hostName = QHostInfo::localHostName();    QHostInfo hostInfo = QHostInfo::fromName(hostName);    QString loaclIP;    QList addList = hostInfo.addresses();    foreach (auto aHost, addList)    {        if(aHost.protocol() == QAbstractSocket::IPv4Protocol)        {            if(loaclIP.isEmpty())            {                loaclIP = aHost.toString();            }            ui->comboBox->addItem(aHost.toString());        }    }    return loaclIP;}void MainWindow::on_StateChanged(QAbstractSocket::SocketState state){    switch (state)    {    case QAbstractSocket::UnconnectedState:        labSocketState->setText("socket状态：UnconnectedState");        break;    case QAbstractSocket::HostLookupState:        labSocketState->setText("socket状态：HostLookupState");        break;    case QAbstractSocket::ConnectingState:        labSocketState->setText("socket状态：ConnectingState");        break;    case QAbstractSocket::ConnectedState:        labSocketState->setText("socket状态：ConnectedState");        break;    case QAbstractSocket::BoundState:        labSocketState->setText("socket状态：BoundState");        break;    case QAbstractSocket::ListeningState:        labSocketState->setText("socket状态：ListeningState");        break;    case QAbstractSocket::ClosingState:        labSocketState->setText("socket状态：ClosingState");        break;    default:        break;    }}void MainWindow::on_SocketReadyRead(){    QByteArray datagram;    datagram.resize(udpSocket->pendingDatagramSize());    QHostAddress peerAddr;    unsigned short peerPort;    udpSocket->readDatagram(datagram.data(), datagram.size(), &peerAddr, &peerPort);    QString str = datagram.data();    QString peer = "[From " + peerAddr.toString() + ":" + QString::asprintf("%d", peerPort) + "] ";    ui->plainTextEdit->appendPlainText(peer  + str);}void MainWindow::on_actStart_triggered(){    quint16 port = ui->spinBoxBindPort->value();    if(udpSocket->bind(port))    {        ui->plainTextEdit->appendPlainText("**已绑定成功");        ui->plainTextEdit->appendPlainText("**端口：" + QString::number(udpSocket->localPort()));        ui->actStart->setEnabled(false);        ui->actStop->setEnabled(true);    }}void MainWindow::on_actStop_triggered(){    udpSocket->abort();    ui->actStart->setEnabled(true);    ui->actStop->setEnabled(false);    ui->plainTextEdit->appendPlainText("**已解除绑定");}void MainWindow::on_actClear_triggered(){    ui->plainTextEdit->clear();}void MainWindow::on_pushButton_clicked(){    // 单播    QString targetIP = ui->comboBox->currentText();    quint16 targetPort = ui->spinBoxPort->value();    QHostAddress targetAddr(targetIP);    QString msg = ui->lineEdit->text();    QByteArray data = msg.toUtf8();    udpSocket->writeDatagram(data, targetAddr, targetPort);    ui->plainTextEdit->appendPlainText("[out] " + msg);    ui->lineEdit->clear();    ui->lineEdit->setFocus();}void MainWindow::on_pushButton_2_clicked(){    // 广播    quint16 targetPort = ui->spinBoxPort->value();    QString msg = ui->lineEdit->text();    QByteArray data = msg.toUtf8();    udpSocket->writeDatagram(data, QHostAddress::Broadcast, targetPort);    ui->plainTextEdit->appendPlainText("[out] " + msg);    ui->lineEdit->clear();    ui->lineEdit->setFocus();}

  2、实现组播程序

  （1）拷贝上一个项目

  （2）修改控件

  （3）实现功能

  #include "mainwindow.h"#include "ui_mainwindow.h"MainWindow::MainWindow(QWidget *parent) :    QMainWindow(parent),    ui(new Ui::MainWindow){    ui->setupUi(this);    labSocketState = new QLabel("Socket状态：");    labSocketState->setMinimumWidth(200);    ui->statusBar->addWidget(labSocketState);    QString localIP = getLocalIP();    setWindowTitle("Udp组播收发器:" + localIP);    udpSocket = new QUdpSocket(this);    connect(udpSocket, SIGNAL(stateChanged(QAbstractSocket::SocketState)),            this, SLOT(on_StateChanged(QAbstractSocket::SocketState)));    connect(udpSocket, SIGNAL(readyRead()),            this, SLOT(on_SocketReadyRead()));}MainWindow::~MainWindow(){    delete ui;}QString MainWindow::getLocalIP(){    QString hostName = QHostInfo::localHostName();    QHostInfo hostInfo = QHostInfo::fromName(hostName);    QString loaclIP;    QList addList = hostInfo.addresses();    foreach (auto aHost, addList)    {        if(aHost.protocol() == QAbstractSocket::IPv4Protocol)        {            if(loaclIP.isEmpty())            {                loaclIP = aHost.toString();            }            ui->comboBox->addItem(aHost.toString());        }    }    return loaclIP;}void MainWindow::on_StateChanged(QAbstractSocket::SocketState state){    switch (state)    {    case QAbstractSocket::UnconnectedState:        labSocketState->setText("socket状态：UnconnectedState");        break;    case QAbstractSocket::HostLookupState:        labSocketState->setText("socket状态：HostLookupState");        break;    case QAbstractSocket::ConnectingState:        labSocketState->setText("socket状态：ConnectingState");        break;    case QAbstractSocket::ConnectedState:        labSocketState->setText("socket状态：ConnectedState");        break;    case QAbstractSocket::BoundState:        labSocketState->setText("socket状态：BoundState");        break;    case QAbstractSocket::ListeningState:        labSocketState->setText("socket状态：ListeningState");        break;    case QAbstractSocket::ClosingState:        labSocketState->setText("socket状态：ClosingState");        break;    default:        break;    }}void MainWindow::on_SocketReadyRead(){    QByteArray datagram;    datagram.resize(udpSocket->pendingDatagramSize());    QHostAddress peerAddr;    unsigned short peerPort;    udpSocket->readDatagram(datagram.data(), datagram.size(), &peerAddr, &peerPort);    QString str = datagram.data();    QString peer = "[From " + peerAddr.toString() + ":" + QString::asprintf("%d", peerPort) + "] ";    ui->plainTextEdit->appendPlainText(peer  + str);}void MainWindow::on_actStart_triggered(){    QString IP = ui->comboBox->currentText();    groupAddress = QHostAddress(IP);    quint16 groupPort = ui->spinBoxBindPort->value();    if(udpSocket->bind(QHostAddress::AnyIPv4, groupPort, QUdpSocket::ShareAddress))    {        udpSocket->joinMulticastGroup(groupAddress);        ui->plainTextEdit->appendPlainText("**加入组播成功");        ui->plainTextEdit->appendPlainText("**组播IP：" + IP);        ui->plainTextEdit->appendPlainText("**组播端口：" + QString::number(groupPort));        ui->actStart->setEnabled(false);        ui->actStop->setEnabled(true);        ui->comboBox->setEnabled(false);    }    else    {        ui->plainTextEdit->appendPlainText("**端口绑定失败");    }}void MainWindow::on_actStop_triggered(){    udpSocket->leaveMulticastGroup(groupAddress);    udpSocket->abort();    ui->actStart->setEnabled(true);    ui->actStop->setEnabled(false);    ui->comboBox->setEnabled(true);    ui->plainTextEdit->appendPlainText("**已退出组播，解除端口绑定");}void MainWindow::on_actClear_triggered(){    ui->plainTextEdit->clear();}void MainWindow::on_btnSend_clicked(){    QString targetIP = ui->comboBox->currentText();    quint16 targetPort = ui->spinBoxBindPort->value();    QHostAddress targetAddr(targetIP);    QString msg = ui->lineEdit->text();    QByteArray data = msg.toUtf8();    udpSocket->writeDatagram(data, targetAddr, targetPort);    ui->plainTextEdit->appendPlainText("[out] " + msg);    ui->lineEdit->clear();    ui->lineEdit->setFocus();}

  四、HTTP通信

  1、相关类

  QNetworkRequest，通过一个URL地址发起网络请求，也保存网络请求信息。QNetworkAccessManager，用于协调网络操作，在QNetworkRequest发起一个网络请求后，负责发送网络请求，创建网络响应。QNwtworkReply，网络请求的响应。

  1、实现基于http协议文件下载

  （1）创建项目

  （2）实现功能

  #include "mainwindow.h"#include "ui_mainwindow.h"#include #include MainWindow::MainWindow(QWidget *parent) :    QMainWindow(parent),    ui(new Ui::MainWindow){    ui->setupUi(this);}MainWindow::~MainWindow(){    delete ui;}#include void MainWindow::on_finished(){    QFileInfo fileInfo;    fileInfo.setFile(downloadFile->fileName());    downloadFile->close();    delete downloadFile;    downloadFile = nullptr;    reply->deleteLater();    reply = nullptr;    if(ui->checkBox->isChecked())    {        QDesktopServices::openUrl(QUrl::fromLocalFile(fileInfo.absolutePath()));        ui->btnDownload->setEnabled(true);    }}void MainWindow::on_readyRead(){    downloadFile->write(reply->readAll());}void MainWindow::on_downloadProgress(qint64 readBytes, qint64 totalBytes){    ui->progressBar->setMaximum(totalBytes);    ui->progressBar->setValue(readBytes);}void MainWindow::on_btnDownload_clicked(){    QString strUrl = ui->lineEditUrl->text();    if(strUrl.isEmpty())    {        QMessageBox::information(this, "error", "请输入正确地址");        return;    }    QUrl newUrl = QUrl::fromUserInput(strUrl);    if(!newUrl.isValid())    {        QMessageBox::information(this, "error",                                 QString::asprintf("无效的URL：%s\n错误信息： %s", strUrl.data(), newUrl.errorString().data()));        return;    }    QString tempDir = ui->lineEditSavePath->text();    if(tempDir.isEmpty())    {        QMessageBox::information(this, "error", "保存路径无效");        return;    }    QString fullFileName = tempDir + newUrl.fileName();    if(QFile::exists(fullFileName))    {        QFile::remove(fullFileName);    }    downloadFile = new QFile(fullFileName);    if(!downloadFile->open(QIODevice::WriteOnly))    {        QMessageBox::information(this, "error", "文件打开失败：" + fullFileName);        return;    }    ui->btnDownload->setEnabled(false);    reply = networkManager.get(QNetworkRequest(newUrl));    connect(reply, SIGNAL(finished()), this, SLOT(on_finished()));    connect(reply, SIGNAL(readyRead()), this, SLOT(on_readyRead()));    connect(reply, SIGNAL(downloadProgress(qint64, qint64)), this, SLOT(on_downloadProgress(qint64, qint64)));}void MainWindow::on_btnDefaultPath_clicked(){    QString curPath = QDir::currentPath();    QDir dir(curPath);    QString sub("temp");    dir.mkdir(sub);    ui->lineEditSavePath->setText(dir.path() + "/" + sub + "/");}

  五、打包程序

  将指定程序打包，将依赖库打包进目录

  D:\Qt\Qt5.13.0.13.0\mingw73_64\bin\windeployqt.exe E:/XXX/xxx.exe