在这里利用QNetworkAccessManager来实现下载文件,经测试,可以使用http或者ftp都可以使用,别的还未测试

    此处使用QT 4.8.6

    首先记得在.pro文件加入network

    QT += core gui network

    //此处用来实现进度条显示

    void Widget::downloadProgress(qint64 a,qint64 b)
    {
    f->write(reply->readAll());
    ui->progressBar->setMaximum(b);
    ui->progressBar->setValue(a);
    }

    //此处当下载完毕,用来刷新和关闭文件

    void Widget::onFinished(QNetworkReply * reply)//reply用于接收消息
    {
    qDebug() << “Your thing had finished downloading.”;
    f->flush();
    f->close();
    reply->deleteLater();
    }

    //此处用来下载和删除文件
    void Widget::on_btnDownload_clicked()
    {
    QFileInfo info(“http://tupian.enterdesk.com/2012/0606/gha/10/11285966_1334673509285.jpg“);

    1. f = new QFile(info.fileName());
    2. f->open(QIODevice::WriteOnly);
    3. reply = manager->get(QNetworkRequest(QUrl("http://tupian.enterdesk.com/2012/0606/gha/10/11285966_1334673509285.jpg")));
    4. connect(reply,SIGNAL(downloadProgress(qint64,qint64)),this,SLOT(downloadProgress(qint64,qint64)));

    }

    void Widget::on_btnDel_clicked()
    {
    QFileInfo info(“http://tupian.enterdesk.com/2012/0606/gha/10/11285966_1334673509285.jpg“);

    1. f = new QFile(info.fileName());
    2. f->remove();

    }