Android – Set fragment id

by

You can’t set a fragment’s ID programmatically.

There is however, a String tag that you can set inside the FragmentTransaction which can be used to uniquely identify a Fragment.

As Aleksey pointed out, you can pass an ID to FragmentTransaction‘s add(int, Fragment) method. However, this does not specify the ID for a Fragment. It specifies the ID of a ViewGroup to insert the Fragment into. This is not that useful for the purpose I expect you have, because it does not uniquely identify Fragments, but ViewGroups. These IDs are of containers that one or more fragments can be added to dynamically. Using such a method to identify Fragments would require you to add ViewGroups dynamically to the Layout for every Fragment you insert. That would be pretty cumbersome.

So if your question is how to create a unique identifier for a Fragment you’re adding dynamically, the answer is to use FragmentTransaction‘s add(int containerViewId, Fragment fragment, String tag) method and FragmentManager‘s findFragmentByTag(String) method.

In one of my apps, I was forced to generate strings dynamically. But it’s not that expensive relative to the actual FragmentTransaction, anyway.

Another advantage to the tag method is that it can identify a Fragment that isn’t being added to the UI. See FragmentTransaction’s add(Fragment, String) method. Fragments need not have Views! They can also be used to persist ephemeral state between config changes!

More Related Contents:

  1. How to implement onBackPressed() in Fragments?
  2. How to determine when Fragment becomes visible in ViewPager
  3. Do fragments really need an empty constructor?
  4. IllegalStateException: Can not perform this action after onSaveInstanceState with ViewPager
  5. How to transfer some data to another Fragment?
  6. Why fragments, and when to use fragments instead of activities?
  7. Programmatically go back to the previous fragment in the backstack
  8. Refresh Fragment at reload
  9. How to implement RecyclerView with CardView rows in a Fragment with TabLayout
  10. Android Fragments. Retaining an AsyncTask during screen rotation or configuration change
  11. Hide/Show bottomNavigationView on Scroll
  12. Difference between android.app.Fragment and android.support.v4.app.Fragment
  13. PreferenceFragmentCompat requires preferenceTheme to be set
  14. android.content.Context.getPackageName()’ on a null object reference
  15. onClickListener does not work in fragment
  16. Detect ViewPager tab change inside Fragment
  17. reusing fragments in a fragmentpageradapter
  18. I get the error “Unreachable statement” return in android
  19. When a Fragment is replaced and put in the back stack (or removed) does it stay in memory?
  20. In Fragment on back button pressed Activity is blank
  21. How do you create Preference Activity and Preference Fragment on Android?
  22. refresh fragment UI from fragmentActivity
  23. Android – save/restore fragment state
  24. findFragmentById always returns null
  25. How to replace the activity’s fragment from the fragment itself?
  26. Communication between Fragments in ViewPager
  27. How to open fragment page, when pressed a notification in android
  28. OnCreateView called multiple times / Working with ActionBar and Fragments
  29. Integrating youtube to fragment
  30. Pop up window to display some stuff in a fragment

Leave a Comment