Interactivity Coordination: onStop and onResume

Question

I have two activities. One loads all rows from a database, and the other saves to the database. When I have the second save in onStop and the first repull the data in onResume, they do it out of order (the first resumes and then the second saves). I managed to fix this by putting the saving data in onPause, but why was this happening? Was this the cleanest way to do it?

Answer 1

Doing the save in the first actvity's onPause should be fine.

You've discovered that the foreground lifetime of an activity happens between a call to onResume() until a corresponding call to onPause(). During this time, the activity is in front of all other activities on screen and is interacting with the user.

When you start the second activity, onPause is called on the first and then interactive control switches to the second, with onStop on the first to be called somewhat in background.

This improves responsiveness and gets the new activity in front of the user ASAP. Consequently, you should try to keep your onPause implementation as fast and efficient as possible.

See the following Android docs for more details on the lifecycle http://developer.android.com/guide/topics/fundamentals.html, but what you have found should work fine for you.