Reading/writing data to binary file

[DiamonDogX]

I am basically writing a bunch of qint32 values to a binary file and I want to be able to seek to an offset of the file and read a value back. So I am doing the following for writing and reading:

QFile file( "MyFile" );
    if( file.open( QFile::WriteOnly | QFile::Truncate ) )
    {
        for( int i = 0; i < 10; i++ )
        {
            qint32 exampleNum = 42;
            file.write( ( char * )( &exampleNum ), sizeof( exampleNum) );
        }
        file.close();
    }

QFile file( "MyFile" );
    if( file.open( QFile::WriteOnly | QFile::Truncate ) )
    {
        for( int i = 0; i < 10; i++ )
        {
            qint32 exampleNum = 42;
            file.write( ( char * )( &exampleNum ), sizeof( exampleNum) );
        }
        file.close();
    }

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QFile file( "MyFile" );
    if( file.open( QFile::ReadOnly ) )
    {
        if( file.seek( 4) )
        {
            char * dataRead = new char[ sizeof( qint32 ) ];
            qint64 numBytesRead = file.read( dataRead, sizeof( qint32 ) );
            if( numBytesRead == sizeof( qint32 ) )
            {
                QByteArray dataBytes( dataRead );
                bool ok = false;
               qint32 value = dataBytes.toInt( &ok ); // "value" ends up 0
                if( ok )
                {
                    cout << value; // never gets here
                }
            }
        }
    }

QFile file( "MyFile" );
    if( file.open( QFile::ReadOnly ) )
    {
        if( file.seek( 4) )
        {
            char * dataRead = new char[ sizeof( qint32 ) ];
            qint64 numBytesRead = file.read( dataRead, sizeof( qint32 ) );
            if( numBytesRead == sizeof( qint32 ) )
            {
                QByteArray dataBytes( dataRead );
                bool ok = false;
               qint32 value = dataBytes.toInt( &ok ); // "value" ends up 0
                if( ok )
                {
                    cout << value; // never gets here
                }
            }
        }
    }

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Seem to be having trouble reading a value back...

[Lykurg]

Hey, just a quick suggestion: you might want have a look at QDataStream. Could make your live much more easier.

[DiamonDogX]

Yeah I've used it before... doesn't seem to be helping me in this case...

[DiamonDogX]

I take that back! I mixed it in with the code, changed some things, and I can read and write the integers now...