How can I refresh a previous activity after the back button is pressed?

Question

I am building an alarm application. I currently have a ListActivity which display the list of alarms and another activity which changes the time of a particular alarm. My problem is, when I decide to enter into the activity to change the time of an alarm and then I press the back button, it does not refresh. However, I've implemented a button that redirects back to the ListActivity and if I press it, the list of alarms are refreshed. How can I, after pressing the back button, refresh the list of alarms?

Answer 1

You should probably override your onResume() to check if the list of alarms have been refreshed so that whenever you come to/come back to your ListActivity, it'll get updated.

Answer 2

In your alarm list activity

use

public void onRestart() {
    // reload your list items if changed and adapter.notifydatastatechange();
}

If you done this in onResume then its call two times first when your activity start n 2nd when your activity restart.