QTextStream crashing program when adding items to combobox

gabor53

Hi,
I use QTextStream to populate a combobox:

        QFile inputFile("C:/Programming/Projects/Folkfriends/combo.txt");

        if(inputFile.open (QIODevice::ReadOnly | QIODevice::Text))
        {
            QTextStream in(&inputFile);
            while(!in.atEnd ())
            {
                QString Material = in.readLine ();
                Material_Combo->addItem (Material)	;
            }
        }

Any idea why the while loop crashes the program? (It gives a message like "Stopped working)?

Thank you.

michelson

For me it seems valid, but if i were you I would try peeking what exactly in.readLine() is returning every time (mayby the file is corrupted?).

QDebug() << "Read string: " <<  Material;

SGaist

Hi,

Maybe a silly question but, did you initialize Material_Combo correctly ?

gabor53

Hi,
I initialized like this:

QComboBox *Material_Combo = new QComboBox;

I checked what in.readLine() returns and found this:

Read Matarial string: "Wood"
Read Matarial string: "Metal"
Read Matarial string: ""
Read Matarial string: ""
Read Matarial string: ""
Read Matarial string: ""
Read Matarial string: ""
Read Matarial string: ""
Read Matarial string: ""
Read Matarial string: ""

The empty strings are keep going until I terminate the program. There are 2 lines in the txt file, Wood and Metal. I think it can't find the end of the file maybe, but I don't know why. Thank you for any ideas.

gabor53

I think it is the while loop. I added this section to the program line by line and the only time, when the program crashed is when I added the while loop. Still don't know though why it crashes.

gabor53

If I take away the ! sign and just use

while(in.atEnd())

the program does not crash though the loop reads nothing. Still don't kn ow why....

michelson

Mayby try this one:

QComboBox *Material_Combo = new QComboBox(this);
do
{
    QString line = in.readLine();
    QDebug() << "line: " << line;
    Material_Combo->addItem(line);
} while (!line.isNull());

It is the same but diffrent... Still the same :D I mean i dont know why it crashes when you use atEnd()however it seems that the file is corrupted since the end of file is not detected (file encoding thing possible..?).

SGaist

Or, since it's a text file:

QFile inputFile("C:/Programming/Projects/Folkfriends/combo.txt");
if (!inputFile.open(QIODevice::ReadOnly | QIODevice::Text))
     return;

while (!inputFile.atEnd()) {
    QByteArray material = inputFile.readLine();
    Material_Combo->addItem (material)  ;
}

?