Qt网络编程知识体系

Qt网络编程基础

Qt直接提供网络编程模块，基于TCP/IP客户端和服务器相关各种类。TCP通信（QTcpSocket/QTcpServer）。UDP通信（QUdpSocket）。还有部分实现HTTP、FTP等网络协议的高级类。如QNetworkRequest/QNetworkAccessManager等。

我们开发过程中，UDP、TCP、HTTP 通信类等，必须在程序中引用 Qt 网络模块，项目配置文件的一条配置语句：QT +=network

QHostInfol类：QHostInfo类为主机名查找提供静态函数，主要用来查询主机信息、包括主机名、ip地址、DNS域名等信息。

QNetworkInterface类，主要用于获取主机所有IP地址和网络接口列表信息。

实例程序

#include "gethostnameipinfo.h"
#include "ui_gethostnameipinfo.h"

#include <QMessageBox>

GetHostNameIPInfo::GetHostNameIPInfo(QWidget *parent)
    : QDialog(parent)
    , ui(new Ui::GetHostNameIPInfo)
{
    ui->setupUi(this);

}

GetHostNameIPInfo::~GetHostNameIPInfo()
{
    delete ui;
}

void GetHostNameIPInfo::getHostNameIP()
{
    // 获取主机名称
    QString StrLocalHostName = QHostInfo::localHostName();
    ui->lineEditHostName->setText(StrLocalHostName);

    // 根据主机名称获取对应的IP地址
    QString StrLocalIpAddress;
    QHostInfo hostinfo = QHostInfo::fromName(StrLocalHostName);
    QList<QHostAddress> ipaddresslist = hostinfo.addresses();

    if(!ipaddresslist.isEmpty()){
        for(int i=0;i<ipaddresslist.size();i++){
            QHostAddress addresshost = ipaddresslist.at(i);
            if(QAbstractSocket::IPv4Protocol == addresshost.protocol()){
                StrLocalIpAddress = addresshost.toString();
                break;
            }
        }
    }
    ui->lineEditIPAddr->setText(StrLocalIpAddress);

}

void GetHostNameIPInfo::on_GetHostNameIP_btn_clicked()
{
    getHostNameIP();
}


void GetHostNameIPInfo::on_GetHostInfo_btn_clicked()
{
    QString strTemp = "";
    QList<QNetworkInterface> netlist = QNetworkInterface::allInterfaces();
    for(int i=0;i<netlist.size();i++){
        QNetworkInterface interface = netlist.at(i);
        strTemp = strTemp + QString::fromLocal8Bit("设备名称:") + interface.name() + "\n";
        strTemp = strTemp + QString::fromLocal8Bit("硬件地址:") + interface.hardwareAddress() + "\n";

        QList<QNetworkAddressEntry> entrylist = interface.addressEntries();
        for(int j=0;j<entrylist.size();j++){
            QNetworkAddressEntry entry = entrylist.at(j);
            strTemp = strTemp + QString::fromLocal8Bit("\tip地址:") + entry.ip().toString() + "\n";
            strTemp = strTemp + QString::fromLocal8Bit("\t子网掩码:") + entry.netmask().toString() + "\n";
            strTemp = strTemp + QString::fromLocal8Bit("\t广播地址:") + entry.broadcast().toString() + "\n";
        }
    }

    QMessageBox::information(this,QString::fromLocal8Bit("主机所有信息"),strTemp,QMessageBox::Ok);
}

#include "dialog.h"
#include "ui_dialog.h"


Dialog::Dialog(QWidget *parent)
    : QDialog(parent)
    , ui(new Ui::Dialog)
{
    ui->setupUi(this);
}

Dialog::~Dialog()
{
    delete ui;
}

QString Dialog::ProtocolTypeName(QAbstractSocket::NetworkLayerProtocol protocol)
{
    switch(protocol){
        case QAbstractSocket::IPv4Protocol:
            return "IPv4 Protocol";
        case QAbstractSocket::IPv6Protocol:
            return "IPv6 Protocol";
        case QAbstractSocket::AnyIPProtocol:
            return "Any IP Protocol";
        default:
            return "Unknown Network Layer Protocol";
    }
}

void Dialog::LookupHostInfoFunc(const QHostInfo &host)
{
    QList<QHostAddress> addresslist = host.addresses();
    for(int i=0;i<addresslist.size();i++){
        QHostAddress address = addresslist.at(i);
        ui->plainTextEdit_DomainIP->append(QString::fromLocal8Bit("协议类型：")+ProtocolTypeName(address.protocol()));
        ui->plainTextEdit_DomainIP->append(QString::fromLocal8Bit("本地IP地址：")+address.toString());
    }
}

void Dialog::on_ClearData_clicked()
{
    ui->plainTextEdit_DomainIP->clear();
}


void Dialog::on_GetDomainIP_clicked()
{
    QString strhostname = ui->lineEdit_InputUrl->text();
    ui->plainTextEdit_DomainIP->append(QString::fromLocal8Bit("你所查询主机信息：")+strhostname);
    QHostInfo::lookupHost(strhostname,this,SLOT(LookupHostInfoFunc(QHostInfo)));
}