I have an activity that loads a listview from a database. When I select an item I show the element in another activity. How do I go back to the previous activity without having to reload the listiview?
You cannot avoid reloading the ListView when you come back from another Activity.
The only way to avoid it is to not call another Activity but do the job in the same Activity showing and hiding Panels.
Activity #2 displaying details about a clicked item in the above ListView.
Then you should be able to start Activity #2 from Activity #1, and then when you 'back' out of Activity #2 you return to Activity #1 without Activity #1 being recreated.
As long as you don't call Activity Finish in Activity #1 when you start Activity #2 you should find Activity #1 is resumed from Activity #2 as you desire.