.dat Files

[A Former User]

Currently trying to read and print a .dat file and have no idea where to start. My goal is to display each line of data on a QLabel. I had this code, but nothing happened.

QFile inputFile(QString("/airplane.dat"));
    inputFile.open(QIODevice::ReadOnly);
    if (!inputFile.isOpen()){
    return;
    }

    QTextStream stream(&inputFile);
    for (QString line = stream.readLine();
         !line.isNull();
         line = stream.readLine()) {
        ui->datText->setText(line);
        qApp->processEvents();
        }

Here is what the .dat file looks like:

Any idea on what to do?

[Christian Ehrlicher]

@WesLow said in .dat Files:

ui->datText->setText("line");

Why do you set a text 'line' instead the content of the variable line in here?

[A Former User]

@Christian-Ehrlicher Did that as a test to make sure it wasn't a GUI issue; forgot to change it back. Let me edit that really quickly...

[J.Hilk]

@WesLow I see processEvent calls, multi calls to readline() where the previous data is thrown away (unused).

your dat file seems to be a simple text file, why don't you simply do:

QTextStream stream(&inputFile);
auto myText = stream.readAll();

//Console output for tests
qDebug() << myText;
//Set text for ui
ui->datText->setText(myText);

[JonB]

@WesLow said in .dat Files:

My goal is to display each line of data on a QLabel

First the file just looks like text. Maybe with tabs where there are multiple spaces, we don't know; what program were you using to view that file when you took the screenshot?

So you just need to do what @J-Hilk says, nothing fancy.

If that works, you will see a single multi-line QLabel (if that is what your ui->datText is).

If you then want to do something about breaking it into "each line", I do not suggest you create and place a QLabel for each line. Unless it's just a learning exercise. A QListView might be a preferable widget to use.

P.S.

I had this code, but nothing happened.

I suspect something did happen. But quickly...!

        ui->datText->setText(line);
        qApp->processEvents();

You should be left at the end with whatever the final line in the file is. I think you are expecting to see each line at a time running past, but with one qApp->processEvents(); per iteration I think it will happen much faster than your eye :)