概述

QT的HTTP操作都是异步的，内部通过线程实现。

相关类：

QNetworkAccessManager 【发送网络请求并接收响应】

QNetworkReply 【服务响应】

QNetworkRequest 【服务请求】

QUrl

要使用这些类，需要在pro文件中加入network模块。QT += network

发送一个GET请求

void TestClass::on_pushButton_2_clicked()
{
    QNetworkRequest request;
    request.setHeader(QNetworkRequest::UserAgentHeader,"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36");
    request.setUrl(QUrl(url));
    QNetworkAccessManager* manager = new QNetworkAccessManager;
    manager->get(request);    // 发送请求

    connect(manager,&QNetworkAccessManager::finished,this,&TestClass::reply_response);
}

void TestClass::reply_response(QNetworkReply* reply)
{
    QString responseText = reply->readAll();    // 获取网页数据
    int responseStatus = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();    // 获取HTTP状态码
}

设置代理

QNetworkProxy类提供了一个网络层代理

QNetworkProxy目前支持的类有QAbstractSocket、QTcpSocket、QUdpSocket、QTcpServer和QNetworkAccessManager

使用方法：

QNetworkProxy proxy;
proxy.setType(QNetworkProxy::Socks5Proxy);    // http代理：QNetworkProxy::HttpProxy
proxy.setHostName("127.0.0.1");
proxy.setPort(1080);
proxy.setUser("username");
proxy.setPassword("password");
m_network->setProxy(proxy);

// 禁用代理
m_network->setProxy(QNetworkProxy::NoProxy);

Cookie相关操作

获取返回的cookie

QNetworkAccessManager* m_network = new QNetworkAccessManager;
...
QNetworkCookieJar* jar = m_network->cookieJar();
QList<QNetworkCookie> list = jar->cookiesForUrl(url);
...

设置cookie

QList<QNetworkCookie> list;
list.append(QNetworkCookie("isAdmin","1"));
QVariant var;
var.setValue(list);
request.setHeader(QNetworkRequest::CookieHeader,var);

设置HTTP头

HTTP头设置有两个方法，分别是：setHeader，setRawHeader

使用setRawHeader就行了，如：

request.setRawHeader("User-Agent","izero v1.0");