void write(QString filename) {
  QChar ch('b');
  QFile mfile(filename);
  if (!mfile.open(QFile::WriteOnly) {
    qDebug() << "Could not open file for writing";
    return;
  }
  QDataStream out(&mfile);
  out.setVersion(QDataStream::Qt_4_8);
  out << ch;
  mfile.close();
}

打开二进制文件并写入“b”（二进制）

void read(QString filename) {
  QFile mfile(filename);
  if (!mfile.open(QFile::ReadOnly)) {
    qDebug() << "Could not open file for reading";
    return;
  }
  QDataStream in(&mfile);
  in.setVersion(QDataStream::Qt_4_8);
  QChar mT;
  in >> mT;
  qDebug() << mT;
  mfile.close();
}

读但不读mT ='b'。如果ch和mT变量是整数，mT=4为什么？我如何写ch（二进制文件）并从二进制文件中读取