<?xml version="1.0" encoding="iso-8859-1"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>Qt 4.6: downloadmanager.cpp Example File (network/downloadmanager/downloadmanager.cpp)</title> <link href="classic.css" rel="stylesheet" type="text/css" /> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr> <td align="left" valign="top" width="32"><a href="http://qt.nokia.com/"><img src="images/qt-logo.png" align="left" border="0" /></a></td> <td width="1"> </td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a> · <a href="classes.html"><font color="#004faf">All Classes</font></a> · <a href="functions.html"><font color="#004faf">All Functions</font></a> · <a href="overviews.html"><font color="#004faf">Overviews</font></a></td></tr></table><h1 class="title">downloadmanager.cpp Example File<br /><span class="small-subtitle">network/downloadmanager/downloadmanager.cpp</span> </h1> <pre><span class="comment"> /**************************************************************************** ** ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:LGPL$ ** Commercial Usage ** Licensees holding valid Qt Commercial licenses may use this file in ** accordance with the Qt Commercial License Agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and Nokia. ** ** GNU Lesser General Public License Usage ** Alternatively, this file may be used under the terms of the GNU Lesser ** General Public License version 2.1 as published by the Free Software ** Foundation and appearing in the file LICENSE.LGPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU Lesser General Public License version 2.1 requirements ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. ** ** In addition, as a special exception, Nokia gives you certain additional ** rights. These rights are described in the Nokia Qt LGPL Exception ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. ** ** GNU General Public License Usage ** Alternatively, this file may be used under the terms of the GNU ** General Public License version 3.0 as published by the Free Software ** Foundation and appearing in the file LICENSE.GPL included in the ** packaging of this file. Please review the following information to ** ensure the GNU General Public License version 3.0 requirements will be ** met: http://www.gnu.org/copyleft/gpl.html. ** ** If you have questions regarding the use of this file, please contact ** Nokia at qt-info@nokia.com. ** $QT_END_LICENSE$ ** ****************************************************************************/</span> #include "downloadmanager.h" #include <QFileInfo> #include <QNetworkRequest> #include <QNetworkReply> #include <QString> #include <QStringList> #include <QTimer> #include <stdio.h> DownloadManager::DownloadManager(QObject *parent) : QObject(parent), downloadedCount(0), totalCount(0) { } void DownloadManager::append(const QStringList &urlList) { foreach (QString url, urlList) append(QUrl::fromEncoded(url.toLocal8Bit())); if (downloadQueue.isEmpty()) QTimer::singleShot(0, this, SIGNAL(finished())); } void DownloadManager::append(const QUrl &url) { if (downloadQueue.isEmpty()) QTimer::singleShot(0, this, SLOT(startNextDownload())); downloadQueue.enqueue(url); ++totalCount; } QString DownloadManager::saveFileName(const QUrl &url) { QString path = url.path(); QString basename = QFileInfo(path).fileName(); if (basename.isEmpty()) basename = "download"; if (QFile::exists(basename)) { <span class="comment">// already exists, don't overwrite</span> int i = 0; basename += '.'; while (QFile::exists(basename + QString::number(i))) ++i; basename += QString::number(i); } return basename; } void DownloadManager::startNextDownload() { if (downloadQueue.isEmpty()) { printf("%d/%d files downloaded successfully\n", downloadedCount, totalCount); emit finished(); return; } QUrl url = downloadQueue.dequeue(); QString filename = saveFileName(url); output.setFileName(filename); if (!output.open(QIODevice::WriteOnly)) { fprintf(stderr, "Problem opening save file '%s' for download '%s': %s\n", qPrintable(filename), url.toEncoded().constData(), qPrintable(output.errorString())); startNextDownload(); return; <span class="comment">// skip this download</span> } QNetworkRequest request(url); currentDownload = manager.get(request); connect(currentDownload, SIGNAL(downloadProgress(qint64,qint64)), SLOT(downloadProgress(qint64,qint64))); connect(currentDownload, SIGNAL(finished()), SLOT(downloadFinished())); connect(currentDownload, SIGNAL(readyRead()), SLOT(downloadReadyRead())); <span class="comment">// prepare the output</span> printf("Downloading %s...\n", url.toEncoded().constData()); downloadTime.start(); } void DownloadManager::downloadProgress(qint64 bytesReceived, qint64 bytesTotal) { progressBar.setStatus(bytesReceived, bytesTotal); <span class="comment">// calculate the download speed</span> double speed = bytesReceived * 1000.0 / downloadTime.elapsed(); QString unit; if (speed < 1024) { unit = "bytes/sec"; } else if (speed < 1024*1024) { speed /= 1024; unit = "kB/s"; } else { speed /= 1024*1024; unit = "MB/s"; } progressBar.setMessage(QString::fromLatin1("%1 %2") .arg(speed, 3, 'f', 1).arg(unit)); progressBar.update(); } void DownloadManager::downloadFinished() { progressBar.clear(); output.close(); if (currentDownload->error()) { <span class="comment">// download failed</span> fprintf(stderr, "Failed: %s\n", qPrintable(currentDownload->errorString())); } else { printf("Succeeded.\n"); ++downloadedCount; } currentDownload->deleteLater(); startNextDownload(); } void DownloadManager::downloadReadyRead() { output.write(currentDownload->readAll()); }</pre> <p /><address><hr /><div align="center"> <table width="100%" cellspacing="0" border="0"><tr class="address"> <td width="40%" align="left">Copyright © 2010 Nokia Corporation and/or its subsidiary(-ies)</td> <td width="20%" align="center"><a href="trademarks.html">Trademarks</a></td> <td width="40%" align="right"><div align="right">Qt 4.6.3</div></td> </tr></table></div></address></body> </html>