android - Could I keep position of ScrollView after back to prev Fragment like ListView?

Question

I have tried to use both ScrollView and ListView.

I figured out that if I use ListView and I click one of items let current fragment be replaced by next fragment and press back button to prev fragment. The scroll position of ListView will keep at same position. But if I use ScrollView, it will not.

I don't understand why they are different? And how can I make ScrollView keep its position after press back button?

Actually, I have searched some answer at StackOverflow. But I want to know the reasons and find an easier way to make ScrollView and ListView have same behavior.

Please help me! Thank you!

Answer 1

Fragments automatically save and restore the states of their Views, as long they have IDs assigned.

So if you assign an ID to your ScrollView, its scroll state can be restored:

<ScrollView android:id="@+id/scrollview"
    ...>