QT下载ftp图片并且在label上显示

getFtpImg(QString ftpFilePath, QString curFileName, QLabel* lb)

{

    QNetworkAccessManager* myNetworkManager = new QNetworkAccessManager(this);

    QNetworkRequest myNetworkRequest;

    QNetworkReply *myNetworkReply;

    QFile* downloadedFile = new QFile(imgPath+"/"+curFileName);

    downloadedFile->open(QIODevice::WriteOnly);

    QUrl url;

    url.setScheme("ftp");

    url.setUserName(config.getSet()->value("FTP_USER_NAME").toString());

    url.setPassword(config.getSet()->value("FTP_PASS_WORD").toString());

    url.setHost(config.getSet()->value("FTP_HOST").toString());

    url.setPort(config.getSet()->value("FTP_PORT").toInt());

    url.setPath(ftpFilePath);

    Mymethod::record("try to download file by:"+url.toString(),PRINT_INFO);

    myNetworkRequest.setUrl(url);

    myNetworkReply = myNetworkManager->get(myNetworkRequest);

    QObject::connect(myNetworkReply,&QNetworkReply::readyRead,[=]{

        downloadedFile->write(myNetworkReply->readAll());

    });

    QObject::connect(myNetworkManager,&QNetworkAccessManager::finished,[=]{

        if(NULL==myNetworkReply)

        {

            Mymethod::record(getCodeLocate()+"myNetworkReply is null.",PRINT_ERR);

            return;

        }

        if(myNetworkReply->error() == QNetworkReply::NoError)

        {

            downloadedFile->close();

            Mymethod::record("download file success:"+curFileName,PRINT_INFO);

            lb->clear();

            QPixmap pixmap =  QPixmap(imgPath+"/"+curFileName);

            //            QImage img;

            //            img.load(imgPath+"/"+curFileName);

            //            img.scaled(500,396, Qt::KeepAspectRatio, Qt::SmoothTransformation);

            //lb->resize(500,396);

            lb->resize(lb->size());

            lb->setPixmap(pixmap.scaled(500,396/*pixmap1.scaled(lb->size()*/,Qt::KeepAspectRatio, Qt::SmoothTransformation) /*QPixmap::fromImage(img)*/);

        }

        else

        {

            Mymethod::record(getCodeLocate()+QString("download file:%1 failed,err:%2").arg(curFileName).arg(myNetworkReply->errorString()),PRINT_ERR);

            downloadedFile->close();

        }

        myNetworkReply->deleteLater();

        downloadedFile->deleteLater();

        QObject::disconnect(myNetworkManager,0,0,0);

        myNetworkManager->deleteLater();

    });

}