append data into QByteArray

Question

I want to write a QString 'str' into QByteArray 'baData'.

The 'baData' is having fixed size 80 Bytes (it's requirment).

If the 'str' size is less than 80, append the remaining data of 'baData' with 0 (zero) value.

I wrote following code, but not working porperly.

void MyClass::CopyData(QByteArray &packet)

{

         packet.truncate(0);
         packet[0] = 0x12;
         packet[1] = 0x34;
         ....

         QByteArray baData;
         baData.resize(80);
         baData = 0;

        QString str = "Hello Wrold";

        baData = str.toLocal8Bit();

        packet.append(baData, 80);

}

packet size is not fixed, but baData size if fixed i.e. 80.

Answer 1

The following works for me:

QByteArray baData;
baData.fill(0, 80);

QString str = "Hello World";
baData.insert(0, str.toLocal8Bit());
baData.resize(80);

Basically how it works is, you fill the QByteArray with 80 bytes of 0s, insert your data in the beginning and then resize it back to 80 bytes.