[solved] QTextstream problems

spode

in header, QFile *file_contenente_elencoParole; QTextStream *leggi_scrivi;

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

if(file_contenente_elencoParole->open(QFile::Text | QFile::ReadWrite | QFile::Append&#41;)
{
    leggi_scrivi = new QTextStream(file_contenente_elencoParole);
    leggi_scrivi->setCodec("UTF-8");
}
leggi_scrivi.operator <<("NEW LINE THAT LEGGI_SCRIVI CAN NOT WRITE....");

}
@

why leggi_scrivi do not write into the file?

dangelog

You're

leaking memory

not flushing the QTextStream

not closing the QFile

octal

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....";
}

}
@

spode

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

goetz

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.

spode

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?

spode

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

octal

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

spode

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