// 获取当前的时间戳，设置下载的临时文件名称 QDateTime dateTime = QDateTime::currentDateTime(); QString date = dateTime.toString("yyyy-MM-dd-hh-mm-ss-zzz"); m_strFileName = QString("E:/%1.tmp").arg(date); connect(this, SIGNAL(finished(QNetworkReply *)), this, SLOT(replyFinished(QNetworkReply *))); } DownloadNetworkManager::~DownloadNetworkManager() { // 终止下载 if (m_pReply != NULL) { m_pReply->abort(); m_pReply->deleteLater(); } } // 设置URL及消息头，开始请求 void DownloadNetworkManager::execute() { m_url = QUrl("http://192.168.*.*/download/2.0.0.zip"); QNetworkRequest request; request.setUrl(m_url); request.setHeader(QNetworkRequest::ContentTypeHeader, "application/zip"); connect(this, SIGNAL(authenticationRequired(QNetworkReply *, QAuthenticator *)), this, SLOT(onAuthenticationRequest(QNetworkReply *, QAuthenticator *))); m_pReply = get(request); connect(m_pReply, SIGNAL(downloadProgress(qint64, qint64)), this, SIGNAL(downloadProgress(qint64, qint64))); connect(m_pReply, SIGNAL(readyRead()), this, SLOT(readyRead())); } void DownloadNetworkManager::replyFinished(QNetworkReply *reply) { // 获取响应的信息，状态码为200表示正常 QVariant statusCode = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute); // 无错误返回 if (reply->error() == QNetworkReply::NoError) { // 重命名临时文件 QFileInfo fileInfo(m_strFileName); QFileInfo newFileInfo = fileInfo.absolutePath() + m_url.fileName(); QDir dir; if (dir.exists(fileInfo.absolutePath())) { if (newFileInfo.exists()) newFileInfo.dir().remove(newFileInfo.fileName()); QFile::rename(m_strFileName, newFileInfo.absoluteFilePath()); } } else { QString strError = reply->errorString(); qDebug() << "Error:" << strError; } emit replyFinished(statusCode.toInt()); } // 用户认证 void DownloadNetworkManager::onAuthenticationRequest(QNetworkReply *reply, QAuthenticator *authenticator) { QByteArray password; password.append("123456"); password = QByteArray::fromBase64(password); QString strPassword(password); authenticator->setUser("wang"); authenticator->setPassword(strPassword); } // 本地写文件 void DownloadNetworkManager::readyRead() { QFileInfo fileInfo(m_strFileName); QFileInfo newFileInfo = fileInfo.absolutePath() + m_url.fileName(); QString strFileName = newFileInfo.absoluteFilePath(); emit fileName(strFileName); // 写文件-形式为追加 QFile file(m_strFileName); if (file.open(QIODevice::Append)) file.write(m_pReply->readAll()); file.close(); }

使用

调用download()接口开始下载，关联downloadProgress信号和槽，可以实时获取下载大小、速度、剩余时间等信息。

// 开始下载
void MainWindow::download()
{
    if (m_pNetworkManager == NULL)
    {
        m_pNetworkManager = new DownloadNetworkManager(this);
        connect(m_pNetworkManager, SIGNAL(downloadProgress(qint64, qint64)), this, SLOT(downloadProgress(qint64, qint64)), Qt::QueuedConnection);
        connect(m_pNetworkManager, SIGNAL(replyFinished(int)), this, SLOT(replyFinished(int)), Qt::QueuedConnection);
        connect(m_pNetworkManager, SIGNAL(fileName(QString)), m_pFileInfoLabel, SLOT(setText(QString)), Qt::QueuedConnection);
    }
    m_pNetworkManager->execute();
    downloadTime.start();
}

// 计算下载大小、速度、剩余时间
void MainWindow::downloadProgress(qint64 bytesReceived, qint64 bytesTotal)
{
    // 总时间
    int nTime = downloadTime.elapsed();

    // 本次下载所用时间
    nTime -= m_nTime;

    // 下载速度
    double dBytesSpeed = (bytesReceived * 1000.0) / nTime;
    double dSpeed = dBytesSpeed;

    //剩余时间
    qint64 leftBytes = (bytesTotal - bytesReceived);
    double dLeftTime = (leftBytes * 1.0) / dBytesSpeed;

    m_pSpeedInfoLabel->setText(speed(dSpeed));
    m_pLeftTimeInfoLabel->setText(timeFormat(qCeil(dLeftTime)));
    m_pFileSizeInfoLabel->setText(size(bytesTotal));
    m_pDownloadInfoLabel->setText(size(bytesReceived));
    m_pProgressBar->setMaximum(bytesTotal);
    m_pProgressBar->setValue(bytesReceived);

    // 获取上一次的时间
    m_nTime = nTime;
}

// 下载完成
void MainWindow::replyFinished(int statusCode)
{
    m_nStatusCode = statusCode;
    QString strStatus = (statusCode == 200) ? QStringLiteral("下载成功") : QStringLiteral("下载失败");
    m_pStatusLabel->setText(strStatus);
}

 

http://blog.csdn.net/liang19890820/article/details/50814339

Qt之HTTP上传/下载（继承QNetworkAccessManager，包括使用了authenticationRequired认证信号）

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