Comparing QString and char*

I am trying to compare QString against char*, but I fail to do that:

Code:

---

void Register::checkKey()
{
    QMessageBox sd;
    QFile kFile("license.key");
    if (!kFile.open(QIODevice::ReadOnly | QIODevice::Text))
    {
        sd.setText("The registration key doesn't exist.\n");
        sd.exec();
        exit(0);
    }
 
    QTextStream key(&kFile);
    QString test = key.readLine();
    kFile.close();
    QString hash = GetMacAddress();
    char ser[22];
    hdidnt(ser);
    QByteArray Id(ser);
    hash += QString::fromUtf8(Id);
    char *crypt = hash.toUtf8().data();
    encrypt(crypt, "key");
    MD5 md;
    if (test != QString::fromUtf8(md.digestString(md.digestString(md.digestString(crypt)))))
    {
        QMessageBox sdf;
        sdf.setText(QString::fromUtf8(md.digestString(md.digestString(md.digestString(crypt)))) + "\n" \
                  + test + "\n" \
                  + QString::number(sizeof(test.toUtf8())) + "\n" \
                    );
        sdf.exec();
        sd.setText("This product must have a valid key.\n");
        sd.exec();
        KeyDialog kDialog;
        kDialog.setKey(QString::fromUtf8(md.digestString(crypt)));
        kDialog.exec();
        exit(0);
    }
 
}

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I tryied also to convert QString to char* then make the comparison but I fail too. Both QString test and md.digestString(md.digestString(md.digestString(cr ypt))) return some value but they unenable to compare.

I would write something like this ...

Code:

---

QByteArray cryptByteArray = hash.toUtf8();
char *crypt = cryptByteArray.data();

---

If you write directly

Code:

---

char *crypt = hash.toUtf8().data();

---

then temporary QByteArray will no longer exists and "crypt" will point to dangled pointer.

Be sure to discard the newline character in case there is one in the file.

Thenks Mr cincirin, it works now.