Going back to the previous activity in android

Question

I go from activity A to B.

Now I want to go back to activity A again. One way is that i do not finish activity A when I start activity B and then just finish activity B.

Questions:

1. If android has destroyed the activity A due to less memory or other issues, then that activity would no longer be there in the back-stack and then what happens when we press the back button on Activity B.

2. How to configure an activity such that if its instance exits, then we go to it other wise we create a new instance?

Thanks and regards, Sunny

Answer 1

The framework already behaves the way you describe. In scenario 1, the system will restore activity A, even if the app process was killed. Of course, the author of activity A would need to write the appropriate code to save and restore state. As for scenario 2, you can Force this behavior by setting the launchMode field in your <activity> tag in your manifest. See the docs: http://developer.android.com/guide/topics/manifest/activity-element.html