Qt6 QNetworkaccessmanager FTP connection and manipulation

[Thiago Dias]

Good afternoon,
and then guys I have a serious problem, I need to make an application in QT 6, however, I have to connect to an FTP server with a user and password, right after, I need to list all the files in a certain directory so that the user can download. I read the documentation, tested several codes but it doesn't connect and reports the following error QNetworkRequest :: ProtocolUnkwonError. Would anyone have a link with content so that I can study about FTP connections in QT 6?

[SGaist]

Hi and welcome to devnet,

The differences between Qt 5 and Qt 6 with regard to the network API are not that big so following the Qt 5 related threads you may find here will still be relevant.

What exactly did you try ?

[artwaw]

@Thiago-Dias Please post the parts relevant to building network requests.

[Thiago Dias]

#include "principalwindow.h"
#include "ui_principalwindow.h"
#include <QMessageBox>
#include <QChartView>
#include <QtCharts/QLineSeries>

#include <QJsonArray>
#include <QJsonDocument>
#include <QJsonObject>
#include <QJsonValue>

#include <QDebug>

QNetworkReply *reply;

PrincipalWindow::PrincipalWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::PrincipalWindow)
{
ui->setupUi(this);

QObject::connect(json, SIGNAL(finished(QNetworkReply*)),
                     this, SLOT(jsonRequestFinished(QNetworkReply*)));
this->jsonRequest();

QObject::connect(ftp, SIGNAL(finished(QNetworkReply*)),
                 this, SLOT(ftpRequestFinished(QNetworkReply*)));

this->ftpRequest();

[...]

}

PrincipalWindow::~PrincipalWindow()
{
delete ui;
}

void PrincipalWindow::ftpRequest(){
QUrl url;
url.setScheme("ftp");
url.setHost("ftp.gazetadaprovincia.jor.br");
url.setPort(21);
url.setUserName("user");
url.setPassword("password");
QNetworkReply* reply = ftp->get(QNetworkRequest(url));
QByteArray data = reply->readAll() ;
qDebug() << data ;

}

void PrincipalWindow::ftpRequestFinished(QNetworkReply* reply){
if(reply->error() == QNetworkReply::NoError) {

    QString strReply = (QString)reply->readAll();
    qDebug() << strReply;

} else {
    qDebug() << reply->error();
}

}

[artwaw]

This looks properly. Strange.
Two things I'd try:

• first, check if the ftp scheme is supported at all (I assume the ftp is of type QNetworkAccessManager): qDebug() << ftp->supportedSchemes();
• when setting options for QUrl add mode as TolerantMode (however this is highly unlikely to solve the problem)

Apart from that I am out of ideas for now.

[JonB]

See QT6 Protocol "ftp" is unknown and https://www.qt.io/blog/qt-network-in-qt-6.