Qt请求http地址数据

QNetworkAccessManager *manager = new QNetworkAccessManager(this);;
QNetworkRequest network_request;
QByteArray post_data;

network_request.setUrl(QUrl("http://109.26.149.57:8080/tsinghuaVC/init/selectAllFolder.action"));
network_request.setHeader(QNetworkRequest::UserAgentHeader,"Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 UBrowser/6.2.4098.3 Safari/537.36");

connect(manager, SIGNAL(finished(QNetworkReply*)),this, SLOT(replyFinished(QNetworkReply*)));

//发送请求
manager->get(network_request); 

void replyFinished(QNetworkReply* reply)
{
    QTextCodec *codec = QTextCodec::codecForName("utf8");
    //使用utf8编码，这样才可以显示中文
    QString all = codec->toUnicode(reply->readAll());
    qDebug() << "= " << all;
    reply->deleteLater();   //最后要释放reply对象
}