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Downloading file using URL in QT



  • Hi,

    All i want to download a file using url in QT and return content as char *.

    i used below code. download is success and content written in a file.

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    #include <QObject>
    #include <QString>
    #include <QtNetwork/QNetworkAccessManager>
    #include <QtNetwork/QNetworkReply>

    class QtDownload : public QObject {
    Q_OBJECT
    public:
    explicit QtDownload();
    ~QtDownload();

    void setTarget(const QString& t);
    

    private:
    QNetworkAccessManager manager;
    QString target;

    signals:
    void done();

    public slots:
    void download();
    void downloadFinished(QNetworkReply* data);
    void downloadProgress(qint64 recieved, qint64 total);
    };
    #include <QCoreApplication>
    #include <QUrl>
    #include <QNetworkRequest>
    #include <QFile>
    #include <QDebug>

    QtDownload::QtDownload() : QObject(0) {
    QObject::connect(&manager, SIGNAL(finished(QNetworkReply*)),this, SLOT(downloadFinished(QNetworkReply*)));
    }

    QtDownload::~QtDownload() {

    }

    void QtDownload::setTarget(const QString &t) {
    this->target = t;
    }

    void QtDownload::downloadFinished(QNetworkReply *data) {
    QFile localFile("/home/roi/Desktop/downloadedfile.txt");
    if (!localFile.open(QIODevice::WriteOnly))
    return;
    const QByteArray sdata = data->readAll();
    localFile.write(sdata);
    qDebug() << sdata;
    localFile.close();

    emit done();
    

    }

    void QtDownload::download() {
    QUrl url = QUrl::fromEncoded(this->target.toLocal8Bit());
    QNetworkRequest request(url);
    QObject::connect(manager.get(request), SIGNAL(downloadProgress(qint64,qint64)), this, SLOT(downloadProgress(qint64,qint64)));

    }

    void QtDownload::downloadProgress(qint64 recieved, qint64 total) {
    qDebug() << recieved << total;
    }
    #include <QtCore>
    int main(int argc, char **argv) {
    QCoreApplication app(argc, argv);
    QtDownload dl;
    dl.setTarget("http://guest:p2guest@192.168.55.3/contents/2/clip/0711WH.xml");

    dl.download();
    //quit when the download is done.
    QObject::connect(&dl, SIGNAL(done()), &app, SLOT(quit()));
    return app.exec();
    

    // return 0;
    }
    #include "main.moc"

    but my requirement is download file return its content as char *.
    and 2nd thing is

    i am using it from a fun named as

    char * downloadfromUrl(std::wstring szUrl)
    {
    QString Url= QString::fromStdWString(szUrl);
    QtDownload dl;
    //dl.setTarget("http://guest:p2guest@192.168.55.3/contents/2/clip/0711WH.xml");
    dl.setTarget(Url);

    dl.download();

    }

    its not complete.

    please help me for completing downloadfromUrl fun as well as downloadFinished().

    it will be great help, please suggest me.

    signature of downloadfromUrl is char *.

    means downloaded content should be return as char *.

    Thanks
    Shashi


  • Lifetime Qt Champion

    Hi,

    Then add a getter function that returns a char pointer to the start of the buffer you used to store the downloaded file.



  • Thanks Sgaist,

    but how i will call. i do not have main(). i have to call it from
    ownloadfromUrl(std::wstring szUrl)
    {

    }

    i do not have
    nt main(int argc, char **argv) {
    QCoreApplication app(argc, argv);



    }

    please suggest.

    Thanks
    shashi


  • Lifetime Qt Champion

    Before any suggestion, you should describe your application more precisely.


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