Is with the same value as the last time it was used

Question

How do I make the value of contador of for start with the same value as the last time it was used? Why this for always starts when I start to activity, and I need him not to start at 1 every time I start at activity, which are often, because so will add me values to the ArrayList.

   for(int contador = 1 ;contador<=myDB.getLastId();contador++){

        testes.add("Data:  "+myDB.getDates(contador)+"        "+myDB.getHour(contador)+"\n"+"Discilpina:  "+myDB.getDisciplina(contador));


    }

Answer 1

One way to solve this is to use SharedPreferences to save your counter number. First instancie:

SharedPreferences config = PreferenceManager.getDefaultSharedPreferences(this);
SharedPreferences.Editor editor = config.edit();

Then on the part of for I would replace it with a do while and take the amount saved in SharedPreferences to perform the loop. It would look like this:

int contador = config.getInt("contador", 1);

  do {
      testes.add("Data:  "+myDB.getDates(contador)+"        "+myDB.getHour(contador)+"\n"+"Discilpina:  "+myDB.getDisciplina(contador));
      contador++;
    } while (contador<=myDB.getLastId());

editor.putInt("contador", contador);
ListAdapter adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,testes);
testList.setAdapter(adapter);

Note that before the do-while the counter is obtained unless and if there is no number1. Then the value of the counter is saved through the editor. And as acklay commented, remove the adapter from inside the loop.

Perhaps it would be better to use a static variable with the counter or change the architecture of your project to a more systematic way but what I went through should solve.