QTextStream Charcaters Problems

How can i evit when i use this code:

Code:

---

QByteArray buffer;
    QByteArray newBuffer;
 
    QFile file("Test.rar");
    file.open(QIODevice::ReadOnly);
    buffer = file.readAll();
    file.close();
 
    QFile temp("temp");
    temp.open(QIODevice::WriteOnly);
 
    QTextStream out(&temp);
    out << buffer;
    temp.close();
 
    temp.open(QIODevice::ReadOnly);
    newBuffer = temp.readAll();
 
    QFile fileOut("TestOut.rar");
    fileOut.open(QIODevice::WriteOnly);
    fileOut.write(newBuffer);
    fileOut.close();

---

that some characters of the original QByteArray when i use QTextStream are replace with "?"

Look, Like This

?it?? = with QTextStream
˜it€€ = without passing to QTextSteam

How can i evit this replacing of unkwown charcaters