I have to read binary file via Qt. In console application I make

Qt Code: 
  1. FILE * fid5 = fopen ("./test_data/source.rgg", "rb");
  2.  
  3.     ...
  4.     for (int i=1; i<=na; i++)
  5.     {
  6.         fread (st+i-1, sizeof (unsigned long), nd2, fid5);
  7.         ...
  8.     }
To copy to clipboard, switch view to plain text mode 

and all work fine. In Qt application I try
Qt Code: 
  1. QString fileName = QFileDialog::getOpenFileName (this, tr("Select
  2. source file"), QDir::currentPath(), tr("All files (*)"));
  3.     if (fileName.isEmpty())
  4.         return;
  5.     ...
  6.  
  7.     QFile * fData = new QFile (fileName);
  8.  
  9.     for (int i=1; i<=na; i++)
  10.     {
  11.         char * colData = new char [nd2*sizeof (unsigned long)];
  12.         qint64 colLength = fData->readLine (colData, nd2*sizeof
  13. (unsigned long));
  14.         if (colLength < 0)
  15.         {
  16.             qDebug () << __PRETTY_FUNCTION__ << QString ("Read error");
  17.             continue;
  18.         }
  19.         QByteArray buff (colData);
  20.         delete [] colData;
  21.         //qDebug () << __PRETTY_FUNCTION__ << i << buff;
  22.  
  23.         QBuffer lBuf (&buff);
  24.         lBuf.open (QIODevice::ReadOnly);
  25.         QDataStream numStr (&lBuf);
  26.         quint64 num;
  27.         for (int ii=0; ii<nd2; ii++)
  28.         {
  29.             numStr >> num;
  30.             qDebug () << __PRETTY_FUNCTION__ << num;
  31.             st[ii] = num;
  32.         }
  33.         ...
  34.     }
To copy to clipboard, switch view to plain text mode 

And for the same file in debug numbers do not read properly.
Thanks a lot.