程序

需要先加入网络模块：在.pro中加入QT+=network

.h
#ifndef NETWORKINFORMATION_H
#define NETWORKINFORMATION_H

#include <QWidget>
#include <QLabel>
#include <QPushButton>
#include <QLineEdit>
#include <QGridLayout>
#include <QMessageBox>

class NetworkInformation : public QWidget
{
    Q_OBJECT

public:
    NetworkInformation(QWidget *parent = 0);
    ~NetworkInformation();
    void getHostInformation();
public slots:
    void slotDetail();
private:
    QLabel *hostLabel;
    QLineEdit *LineEditLocalHostName;
    QLabel *ipLabel;
    QLineEdit *LineEditAddress;
    QPushButton *detailBtn;
    QGridLayout *mainLayout;
};

#endif // NETWORKINFORMATION_H

.cpp
#include "networkinformation.h"
#include <QHostInfo>
#include <QNetworkInterface>

NetworkInformation::NetworkInformation(QWidget *parent)
    : QWidget(parent)
{
    hostLabel = new QLabel(tr("主机名："));
    LineEditLocalHostName = new QLineEdit;
    ipLabel = new QLabel(tr("IP 地址："));
    LineEditAddress = new QLineEdit;
    detailBtn = new QPushButton(tr("详细"));
    mainLayout = new QGridLayout(this);
    mainLayout->addWidget(hostLabel,0,0);
    mainLayout->addWidget(LineEditLocalHostName,0,1);
    mainLayout->addWidget(ipLabel,1,0);
    mainLayout->addWidget(LineEditAddress,1,1);
    mainLayout->addWidget(detailBtn,2,0,1,2);
    getHostInformation();
    connect(detailBtn,SIGNAL(clicked()),this,SLOT(slotDetail()));
}

NetworkInformation::~NetworkInformation()
{

}

void NetworkInformation::getHostInformation()
{
    QString localHostName = QHostInfo::localHostName();//获取本机主机名
    LineEditLocalHostName->setText(localHostName);
    QHostInfo hostInfo=QHostInfo::fromName(localHostName);//根据主机名获得相关IP信息
    QList<QHostAddress>  listAddress =hostInfo.addresses();
    if(!listAddress.isEmpty())
    {
        LineEditAddress->setText(listAddress.at(2).toString());
    }
}

void NetworkInformation::slotDetail()
{
    QString detail="";
    QList<QNetworkInterface> list=QNetworkInterface::allInterfaces();//获取网络接口
    for(int i=0;i<list.count();i++)
    {
        QNetworkInterface interface=list.at(i);
        detail=detail+tr("设备：")+interface.name()+"\n";
        detail=detail+tr("硬件地址：")+interface.hardwareAddress()+"\n";
        QList<QNetworkAddressEntry>entryList=interface.addressEntries();//返回网络接口的IP地址和子网掩码、广播地址
        for(int j=1;j<entryList.count();j++)
        {
            QNetworkAddressEntry entry=entryList.at(j);
            detail=detail+"\t"+tr("IP 地址：")+entry.ip().toString()+"\n";
            detail=detail+"\t"+tr("子网掩码：")+entry.netmask().toString() +"\n";
            detail=detail+"\t"+tr("广播地址：")+entry.broadcast().toString() +"\n";
        }
    }
    QMessageBox::information(this,tr("Detail"),detail);
}

效果展示