onActivityResult not being called after setResult

Question

I have an activity A - which holds 3 fragments in a Viewpager. Fragment number 1, is a list of news articles, when the user selects a news article from the list, activity B starts and shows the details (title, body, comments) of the article selected. I would like for the user to be able to choose which fragment of activity A he wants to return to, by using the options menu.

Activity A:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    switch (resultCode) {
    case 0:
        mPager.setCurrentItem(0);
        break;
    case 1:
        mPager.setCurrentItem(1);
        break;
    case 2:
        mPager.setCurrentItem(2);
        break;
    }
}

Activity B:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    Intent intent = new Intent(this, MainActivity.class);
    switch (item.getItemId()) {
        case R.id.menu_noticias:
            //startActivityForResult(intent, 0);
            setResult(0, intent);
            finish();
            return true;
        case R.id.menu_contactos:
            //startActivityForResult(intent, 1);
            setResult(1, intent);
            finish();
            return true;
        case R.id.menu_cumples:
            //startActivityForResult(intent, 2);
            setResult(2, intent);
            finish();
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}

Answer 1

You shouldn't call startActivityForResult from activity B. From A, you start activity B by calling startActivityForResult and then from B it's enough setting the result and finishing the activity

Activity A:

Intent intent = new Intent();
...
startActivityForResult(intent, 0);

Activity B:

case R.id.menu_noticias:
    intent.putExtra("menu", 0);
    setResult(RESULT_OK, intent);
    finish();
    return true;

Then on activity A:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
        int menu = data.getExtraInt("menu");
        switch (menu) {
        case 0:
            mPager.setCurrentItem(0);
            break;
        }
    }
}