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Thread: Write NULL character to a file

  1. #1
    Join Date
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    Default Write NULL character to a file

    Hello,

    I have try to find the answer, but didn't have found one. I have a small problem to write NULL character to a file, the problem is that the character is not write.

    Could somebody help me ?

    I have tried with QDataStream but It's add many NULL char that I don't want.

    Thanks.


    This is the code that I use :

    Qt Code:
    1. QFile file("out.txt");
    2. if (!file.open(QIODevice::WriteOnly))
    3. return;
    4.  
    5. QRgb* rgb = (QRgb*)image.scanLine(0);
    6.  
    7. for (int x = 0; x < image.width(); x++)
    8. {
    9. int AlphaValue = qAlpha(rgb[x]);
    10. int RedValue = qRed(rgb[x]);
    11. int GreenValue = qGreen(rgb[x]);
    12. int BlueValue = qBlue(rgb[x]);
    13.  
    14.  
    15. QString AlphaAscii ((QChar)AlphaValue);
    16.  
    17. file.write(qPrintable(AlphaAscii));
    18.  
    19. //file.write((const char *)AlphaAscii.toAscii());
    20.  
    21. }
    22.  
    23. file.close();
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    Last edited by madshiva; 17th October 2011 at 17:13.

  2. #2
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    Default Re: Write NULL character to a file

    You can't write a null character using qPrintable because it terminates when \0 is encountered. Besides your code doesn't make any sense, you can cast between int and QChar.

    Why don't you write the values directly?
    Qt Code:
    1. for(...) {
    2. file.write((const char*)(rgb+x), 4);
    3. }
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  3. The following user says thank you to wysota for this useful post:

    madshiva (18th October 2011)

  4. #3
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    Default Re: Write NULL character to a file

    Ok. Thanks you very much for your help !

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