[Qt-interest] Using qDebug with a QBitArray and QDataStream

[Thiago Macieira]

On Wednesday, 2 de February de 2011 08:41:29 Alex Strickland wrote:
> Hi
> 
> Can someone tell me why this doesn't work?:
> 
>          QByteArray debugByteArray;
>          QDataStream debugStream( &debugByteArray, QIODevice::ReadWrite);
>          QBitArray z( 10 );
>          z.setBit( 3, true );
>          debugStream << z;
>          qDebug() << debugByteArray;
> 
> or should I say doesn't do what I expect, the output is:
> 
> "

Right, it does work, it just doesn't output what you expected. You're trying 
to see the debug output of a binary byte array. What happens here is that 
there are embedded NULs inside that array and qDebug got confused.

qDebug is not meant for binary data. It will result in an incomplete output if 
it gets one.

> 
> I know I can do this:
> 
> 	QString text;
> 	for (int i = 0; i < z.size(); ++i)
>      		text += z.testBit(i) ? "1": "0";
> 	qDebug() << text;
> 
> so this more about my education than solving my problem!

Here you're sending text to the debugging output. This is expected to work.

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
  Senior Product Manager - Nokia, Qt Development Frameworks
      PGP/GPG: 0x6EF45358; fingerprint:
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