How get sub partition from QBtyeArray of Hex

looterhunter

hi everyone,

I have a hex data like below:

4200A0DFFD8FFE000104A4649FFD900000
this is just example, the real data is vary long

and I want to get interval FFD8 ... FFD9 , and How I to do it .

    QString str = "4200A0DFFD8FFE000104A4649FFD900000";
    QByteArray myHexArray = QByteArray::fromHex(str.toUtf8());

    //QByteArray head = QByteArray::fromHex("FFD8");
    QByteArray head("FFD8");
    QByteArray tail = QByteArray::fromHex("FFD9");
    QByteArray realHexData;
    //realHexData.resize();

    ui->plainTextEdit->setPlainText(QString::number(myHexArray.indexOf(head)));

My goal is realHexData content is below , and it hex data
realHexData = "FFD8FFE000104A4649FFD9";

How can I do better?

I just think QByteArray::indexOf, but it's not work :(

has another one have better method for me

thank you very much

mrjj

@looterhunter said:

QByteArray

and
http://doc.qt.io/qt-5.5/qbytearray.html#mid
is no good?

looterhunter

@mrjj
hi dear mrjj

yes, I use the QByteArray::mid API solved my problem finally

at first , I not get the head and tail index, but now it's can work, I can get the index

the key point like this:

realHexData = myHexArray.mid(ihead,itail-ihead+2);