[TOC] ## 概述 QNetworkAccessManager是一套API库，可以发包，设置代理，内存配置等。可以用于网络的应答（如http协议）。 1. 当请求完成后，用户需要手动删除QNetworkReply对象，这里要注意，不应该在finished()信号过来的时候删除，而应该使用deleteLater()函数。 2. 如果要并行处理，这里取决于平台，目前桌面平台支持6个并行。 ## 示例 ### 异步读取 ``` #include "widget.h" #include "ui_widget.h" #include <QNetworkAccessManager> #include <QNetworkReply> #include <QDebug> #include <QNetworkReply> Widget::Widget(QWidget *parent) : QWidget(parent), ui(new Ui::Widget) { ui->setupUi(this); m_manager = new QNetworkAccessManager(this); connect(m_manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(replyFinished(QNetworkReply*))); QUrl url("http://www.baidu.com"); m_netWorkReply = m_manager->get(QNetworkRequest(url)); connect(m_netWorkReply, SIGNAL(downloadProgress(qint64,qint64)), this, SLOT(netWorkReplyLoadProgress(qint64,qint64))); connect(m_netWorkReply, SIGNAL(readyRead()), this, SLOT(httpRead())); } Widget::~Widget() { delete ui; } void Widget::replyFinished(QNetworkReply *reply) { qDebug() << "reply->readAll():" << QString::fromUtf8(reply->readAll()); m_netWorkReply->deleteLater(); //此列子中 m_netWorkReply->deleteLater(); 与 delete m_netWorkReply; 没有什么区别 } void Widget::netWorkReplyLoadProgress(qint64 received, qint64 total) { qDebug() << "received:" << received << " total:" << total; } void Widget::deleteNetWorkReply() { qDebug() << "deleteNetWorkReply called!" << endl; } void Widget::httpRead() { qDebug() << "httpRead"; } ``` ### User-Agent ``` QNetworkRequest request; request.setUrl(QUrl("http://qt-project.org")); request.setRawHeader("User-Agent", "MyOwnBrowser 1.0"); QNetworkReply *reply = manager->get(request); connect(reply, SIGNAL(readyRead()), this, SLOT(slotReadyRead())); connect(reply, SIGNAL(error(QNetworkReply::NetworkError)), this, SLOT(slotError(QNetworkReply::NetworkError))); connect(reply, SIGNAL(sslErrors(QList<QSslError>)), this, SLOT(slotSslErrors(QList<QSslError>))); ```