[TOC] ## 概述 QNetworkAccessManager是一套API庫，可以發包，設置代理，內存配置等。可以用于網絡的應答（如http協議）。 1. 當請求完成后，用戶需要手動刪除QNetworkReply對象，這里要注意，不應該在finished()信號過來的時候刪除，而應該使用deleteLater()函數。 2. 如果要并行處理，這里取決于平臺，目前桌面平臺支持6個并行。 ## 示例 ### 異步讀取 ``` #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(); 與 delete m_netWorkReply; 沒有什么區別 } 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>))); ```