android - Saving Activity State in the onPause

Question

I have a variable that I have successfully saved and restored using onSaveInstanceState

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState); // the UI component values are saved here.
    outState.putDouble("VALUE", liter);
    Toast.makeText(this, "Activity state saved", Toast.LENGTH_LONG).show();
}

But this only works if the activity is destroyed. I want to save the same variable by overriding the onPause() method and getting back when the activity is not not paused anymore any ideas on how to do this are greatly appreciated

Answer 1

As you have discovered, onSaveInstanceState is useful only in situations where you need to recreate the same so-called "instance" of the Activity after it has been destroyed by the OS, usually because it is too far in the back stack to stay alive under memory pressure.

Saving your data in onPause is indeed the way to go for persistence that lasts beyond a single execution of your Activity. To get this working, you have several options, including:

• Shared Preferences
• Files
• Databases
• Content Providers

I suggest reading this documentation to learn more about each of these options:

http://developer.android.com/guide/topics/data/data-storage.html