I have a Text File and I'm reading from him 3 lines.

 QFile file(":/sources/expenses.txt");
    {
        if (file.open(QIODevice::ReadOnly | QIODevice::Text))
        {
            QTextStream in(&file);
            in.setCodec("UTF-8");

            while(!in.atEnd())
            {
                ui->DrawTitle->setText(in.readLine());
                ui->DrawDescrip->setText(in.readLine());
                ui->DrawCash->setText(in.readLine());
            }

            file.close();
        }
    }

I want to read three other, random lines every use of this function. For example:

//TEXT FILE
1 line
2 line
3 line
4 line 
5 line
6 line

Running the read function reads first lines (1 line, 2 line, 3 line) and other one time she reads (4 line, 5 line, 6 line) e.t.c

Can you help me?