There are return codes for type in ZBarSymbol. You will be looking for ZBAR_QRCODE for QR codes
Something like this should help you to get the symbol out:
- (void) readerView: (ZBarReaderView*) view didReadSymbols: (ZBarSymbolSet*) syms fromImage: (UIImage*) img
{
//do something useful with results and display resultText in resultViewController
for(ZBarSymbol *sym in syms)
{
imageResult3.image = img;
resultText.text = sym.typeName;
resultText.text = [ resultText.text stringByAppendingString:@" - " ];
resultText.text = [ resultText.text stringByAppendingString:sym.data ];
}
}