title: QT Reading binary file and then convert it to QString
body: <p>I saved the QString in the file like this:</p>
  
  <pre><code>QString str="blabla";
  QByteArray _forWrite=QByteArray::fromHex(str.toLatin1());
  f.write(_forWrite); // f is the file that is opened for writing.
  </code></pre>
  
  <p>Then when I read the file I use QFile::readAll() to take the QByteArray but I don't know how to convert it to QString. </p>
  
  <p>I tried to use the constructor that uses QByteArray but It didn't work out. I tried also with QByteArray::data() but same result. What I do wrong ?</p>