Attempt to invoke virtual method 'void androidx.recyclerview.widget.RecyclerView.setLayoutManager(androidx.recyclerview..)' on a null object reference

Question

I want to write a good chat application with bottom navigation using Fragments. In ChatsFragment.kt I got a problem: enter image description here

My fun onCreateView() in ChatsFragment:

override fun onCreateView(
    inflater: LayoutInflater, container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {

    usersRecycler.layoutManager = LinearLayoutManager(this, RecyclerView.VERTICAL, false)

    var userlist = ArrayList<User>()
    userlist.add(User("Squirrel", "https://wampi.ru/image/RjQ3yNw"))
    userlist.add(User("Adam", "https://wampi.ru/image/RjQ3yNw"))


    var userAdapter = UserAdapter(requireActivity(), userlist)
    usersRecycler.adapter = userAdapter
    // Inflate the layout for this fragment
    return inflater.inflate(R.layout.fragment_chats, container, false)

}

Exception on usersRecycler.layoutManager = LinearLayoutManager(this, RecyclerView.VERTICAL, false)

I read a lot of solutions like: "replace "this" to requiredActivity() or requiredContext()", but nothing helped, throwing out this error: Attempt to invoke virtual method 'void androidx.recyclerview.widget.RecyclerView.setLayoutManager(androidx.recyclerview.widget.RecyclerView$LayoutManager)' on a null object reference

I also wanted replace Fragments on Activity as bottom navigation. Would that be the wrong decision?

How can I resolve this problem? Help me, android developers, please...

Answer 1

To solve this issue you need to pass the context of fragment. in Kotlin below code can solve your problem. Just pass "activity"

   val layoutManager = LinearLayoutManager(activity)

You can also user

 layoutManager = LinearLayoutManager(requireActivity())

Both will return the getActivity() instance.

Please let me know if you still face the error will help you for sure.

Thanks