Hello,
Qt Code: 
  1. void write(QString filename) {
  2.   QChar ch('b');
  3.   QFile mfile(filename);
  4.   if (!mfile.open(QFile::WriteOnly) {
  5.     qDebug() << "Could not open file for writing";
  6.     return;
  7.   }
  8.   QDataStream out(&mfile);
  9.   out.setVersion(QDataStream::Qt_4_8);
  10.   out << ch;
  11.   mfile.close();
  12. }
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open binary file and writing ‘b’(binary)
Qt Code: 
  1. void read(QString filename) {
  2.   QFile mfile(filename);
  3.   if (!mfile.open(QFile::ReadOnly)) {
  4.     qDebug() << "Could not open file for reading";
  5.     return;
  6.   }
  7.   QDataStream in(&mfile);
  8.   in.setVersion(QDataStream::Qt_4_8);
  9.   QChar mT;
  10.   in >> mT;
  11.   qDebug() << mT;
  12.   mfile.close();
  13. }
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read but not mT=‘b’.if ch and mT variables are int always mT=4 why?How can i writing ch(binary file) and read from binary file
im working huffman encode project.I have all i needs(freq table,char code…)but i was writing code i cant earning size.I think this problem reason is opened binary and writing problem.How can i opened binary file and writing variables bytes.

for example;
Qt Code: 
  1. int x=4;
  2. QString abc="hello";
  3. char ch ='a';
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How can i writing them file.Thanks for all helping now.