Question

I have two activities, activity 1 and activity 2 for example. Activity 1 will call activity 2 and send an arraylist which will then be modified. This I have already done using an intent. What I now want to do, is when activity 2 calls finish() I want that modified arraylist to be sent back to activity 1 so that it has the most upto date version of that arraylist.

Activity 1:

Bundle b = new Bundle();
b.putParcelableArrayList("com.Woody.RingerSchedule", schedules);
Intent i = new Intent(this, addSchedule.class);
i.putExtras(b);
startActivity(i);

Activity 2 so far:

Bundle b = getIntent().getExtras();
final ArrayList<Schedule> schedules = b.getParcelableArrayList("com.Woody.RingerSchedule");
//modify arraylist
//need code here to return arraylist to activity 1
finish();

Any help appreciated.

Answer 1

You need to call setResult with the Intent param

Intent intent = new Intent();
intent.putExtra("returnKey","test");
setResult(RESULT_OK,intent);
finish();

You read from the activity that started the activity with startActivityForResult

//we need a handler for when the secondary activity finishes it's work
//and returns control to this activity...
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent){
    super.onActivityResult(requestCode, resultCode, intent);
    Bundle extras = intent.getExtras();
    mEditText1.setText(extras != null ? extras.getString("returnKey"):"nothing returned");
}

See this for more example: http://www.remwebdevelopment.com/dev/a33/Passing-Bundles-Around-Activities.html