[solved] QTextstream problems

[dangelog]

You're

leaking memory

not flushing the QTextStream

not closing the QFile

[A Former User]

bq. in header, QFile *file_contenente_elencoParole; QTextStream *leggi_scrivi;

How do you justify the usage of pointers here (except for leaking memory :D) ?

[giesbert]

Why do you use pointers here?
I would prefer using local stack variables:

@
Gestore::Gestore(QObject *parent) :
QObject(parent)
{
QDir dir;
dir.mkpath("C:/WoerterErinnerung");
QFile file_contenente_elencoParol("C:/WoerterErinnerung/elencoParoleSalvate.txt");

if(file_contenente_elencoParole.open(QFile::Text | QFile::ReadWrite | QFile::Append))
{
    QTextStream leggi_scrivi(&file_contenente_elencoParole);
    leggi_scrivi.setCodec("UTF-8");
    leggi_scrivi  << "NEW LINE THAT LEGGI_SCRIVI CAN NOT WRITE....";
}

}
@

[A Former User]

i would to use leggi_scrivi as a global variable...

[giesbert]

Global? uähhh....
perhaps as member in a class, but I would not use globaö variiables if possible.

But you could call "QTextStream::flush":http://doc.qt.nokia.com/4.7/qtextstream.html#flush

[A Former User]

If you are using [[Doc:QTextStream]] then please do not set the QFile::Text flag, that's useful for plain files only.

Also, you should use QIODevice::xxx flags, as those are defined in [[Doc:QIODevice]] not in [[Doc:QFile]].

This works:

@
QFile file("/tmp/qdn-test.txt");
if(file.open(QIODevice::WriteOnly | QIODevice::Append)) {
QTextStream ts(&file);
ts.setCodec("UTF-8");
ts << "Test for DevNet Users" << "\n";
ts << "more text" << "\n";
file.close();
}
@

The file contents are likely to be not written to the disk until the file is closed, so you might see some leaks.

[A Former User]

ok, also why this snippet dows not work?
@
QFile file_contenente_elencoParole("C:/WoerterErinnerung/elencoParoleSalvate.txt");
if(file_contenente_elencoParole.open(QIODevice::ReadWrite | QIODevice::Append))
{
QTextStream leggi_scrivi(&file_contenente_elencoParole);
leggi_scrivi.setCodec("UTF-8");
leggi_scrivi << "prova" << endl;
qDebug() << leggi_scrivi.readLine();
}
@

[dangelog]

Can you define "does not work"? No file is created? The file is created but it's empty? The contents are different from the expected ones?

[A Former User]

QTextStream writes but does not read...
qDebug() << leggi_scrivi.readLine();
returns "".

[A Former User]

I guess you're at the end of the device. Thus you get an empty string when trying to read.

I would call @leggi_scrivi.seek(0)@ before

[A Former User]

thank you!!!! you are simply a wizard!