protocol() QAbstractSocket::NetworkLayerProtocol类型变量，表示当前IP地址的协议类型  类型如下：

　　QAbstractSocket::IPv4Protocol

　　QAbstractSocket::IPv6Protocol

　　QAbstractSocket::AnyIPProtocol

　　QAbstractSocket::UnknowNetworkLayerProtocol

toString() 返回IP地址的字符串，表示程序中显示了IP地址列表中每个IP地址的协议类型和IP地址字符串


#ifndef MAINWINDOW_H

#define MAINWINDOW_H

#include <QMainWindow>

#include <QAbstractSocket>

#include <QHostInfo>

#include <QNetworkInterface>

#include <QHostAddress>

namespace Ui {

class MainWindow;

}

class MainWindow : public QMainWindow

{

    Q_OBJECT

public:

    explicit MainWindow(QWidget *parent = nullptr);

    ~MainWindow();

private slots:

    void on_pushButton_clicked();

    void on_pushButton_2_clicked();

    void on_pushButton_3_clicked();

    void on_pushButton_4_clicked();

    void on_pushButton_5_clicked();

    void lookedUpHostInfo(const QHostInfo &info);

private:

    Ui::MainWindow *ui;

    QString protoclName(QAbstractSocket::NetworkLayerProtocol protocol);

};

#endif // MAINWINDOW_H

#include "mainwindow.h"

#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :

    QMainWindow(parent),

    ui(new Ui::MainWindow)

{

    ui->setupUi(this);

}

MainWindow::~MainWindow()

{

    delete ui;

}

void MainWindow::on_pushButton_clicked()

{

    //获取主机信息

    QString hostname = QHostInfo::localHostName(); //本地主机名

    ui->plainTextEdit->appendPlainText("本地主机名："+hostname+"\n");

    QHostInfo hostinfo = QHostInfo::fromName(hostname); //本机IP

    QList<QHostAddress> addList = hostinfo.addresses();// IP地址列表

    if(!addList.isEmpty())

    {

        for(int i =0;i<addList.count();i++)

        {

            QHostAddress aHost = addList.at(i);

            bool show = ui->checkBox->isChecked(); //只显示IPV4

            if(show)

            {

                show = (QAbstractSocket::IPv4Protocol == aHost.protocol());

            }else {

                show = true;

            }

            if(show)

            {

                ui->plainTextEdit->appendPlainText("协议："+protoclName(aHost.protocol()));

                ui->plainTextEdit->appendPlainText("本机IP地址："+aHost.toString());

                ui->plainTextEdit->appendPlainText("");

            }

        }

    }

}

void MainWindow::on_pushButton_2_clicked()

{

    QList<QHostAddress> list = QNetworkInterface::allAddresses();

        if(!list.isEmpty())

        for(int i =0;i<list.count();i++)

        {

            QHostAddress aHost = list.at(i);

            bool show = ui->checkBox->isChecked();

            if(show)

                show=QAbstractSocket::IPv4Protocol == aHost.protocol();

            else

                show =true;

            if(show)

            {

                ui->plainTextEdit->appendPlainText("协议"+protoclName(aHost.protocol()));

                ui->plainTextEdit->appendPlainText("IP地址"+aHost.toString());

                ui->plainTextEdit->appendPlainText("");

            }

        }

}

void MainWindow::on_pushButton_3_clicked()

{

    QList<QNetworkInterface> list = QNetworkInterface::allInterfaces();

    for(int i=0;i<list.count();i++)

    {

        QNetworkInterface aInterface = list.at(i);

        if(!aInterface.isValid())

        {

            continue;

        }

        ui->plainTextEdit->appendPlainText("设备名称"+aInterface.humanReadableName());

        ui->plainTextEdit->appendPlainText("硬件地址"+aInterface.hardwareAddress());

        QList<QNetworkAddressEntry> entry = aInterface.addressEntries();

        for(int j = 0;j<entry.count();j++)

        {

            QNetworkAddressEntry aEntry = entry.at(j);

            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() + "\n");

        }

        ui->plainTextEdit->appendPlainText("\n");

    }

}

void MainWindow::on_pushButton_4_clicked()

{

    QString hostname = ui->lineEdit->text(); //主机名

    ui->plainTextEdit->appendPlainText("正在查找主机信息"+ hostname);

    QHostInfo::lookupHost(hostname,this,SLOT(lookedUpHostInfo(QHostInfo)));

}

void MainWindow::on_pushButton_5_clicked()

{

    ui->plainTextEdit->clear();

}

void MainWindow::lookedUpHostInfo(const QHostInfo & info)

{

    QList<QHostAddress> addList = info.addresses();

    if(!addList.isEmpty());

    for(int i =0;i < addList.count(); i++)

    {

        QHostAddress aHost = addList.at(i);

        bool show = ui->checkBox->isChecked();

        if(show)

            show = QAbstractSocket::IPv4Protocol ==aHost.protocol();

        else

            show = true;

        if(show)

        {

            ui->plainTextEdit->appendPlainText("协议"+protoclName(aHost.protocol()));

            ui->plainTextEdit->appendPlainText(aHost.toString());

        }

    }

}

//根据protocol()返回的QabstractSocket::NetworkLayerProtocol  枚举值显示协议名称字符串

QString MainWindow::protoclName(QAbstractSocket::NetworkLayerProtocol protocol)

{

    switch (protocol)

    {

    case QAbstractSocket::IPv4Protocol:

        return "IPV4 Protocol";

    case QAbstractSocket::IPv6Protocol:

        return "IPV4 Protocol";

    case QAbstractSocket::AnyIPProtocol:

        return "IPV4 Protocol";

    default:

        return "Unknow Network Layer Protocol";

    }

}

Qt 实现主机信息查询