CODEWITHSUNDEEP
androidandroid-fragmentsandroid-viewbinding
kirvel
kirvel

Reputation: 671

ViewBinding in Fragment

I want to use ViewBinding to work with Views in Fragment.

FragmentBlankBinding binding;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    binding = FragmentBlankBinding.inflate(inflater, container, false);
    return binding.getRoot();
}

But when I try to get RecyclerView from that binding like this:

binding.notesRecyclerView.setAdapter(adapter);

I get NullPointerException:

java.lang.NullPointerException: Attempt to read from field 'androidx.recyclerview.widget.RecyclerView com.myapps.notes.databinding.FragmentBlankBinding.notesRecyclerView' on a null object reference

P.S. here's fragment_blank.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context=".BlankFragment">

    <com.getbase.floatingactionbutton.FloatingActionButton
        android:id="@+id/newNoteActionButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentEnd="true"
        android:layout_margin="3dp"
        android:elevation="10dp"
        app:fab_icon="@drawable/ic_baseline_add_24" />

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/notesRecyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager" /> 
</RelativeLayout>

Upvotes: 30

Views: 55903

Answers (7)

Mudit Goel
Mudit Goel

Reputation: 354

For Fragments following implementation of view binding works for me :

class HomeFragment : Fragment() {
    private lateinit var viewModel: HomeViewModel
    private lateinit var binding: FragmentHomeBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = FragmentHomeBinding.inflate(layoutInflater)
    }

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        viewModel = ViewModelProvider(this)[HomeViewModel::class.java]
        binding = FragmentHomeBinding.inflate(inflater, container, false)

        binding.txtVw.text = menuItem.title
        binding.imgVwIcon.setImageResource(menuItem.iconId)

        return binding.root
    }
}

Upvotes: 0

Ali Doran
Ali Doran

Reputation: 556

Considering the below link

developer.android

I prefer to implement it in this way. There is a little difference in limitations for manipulating binding.

class SignInFragment : Fragment() {
private var _binding: FragmentSignInBinding? = null
private val binding get() = _binding!!

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    arguments?.let {

    }
}

override fun onCreateView(
    inflater: LayoutInflater, container: ViewGroup?,
    savedInstanceState: Bundle?
): View {
    _binding = FragmentSignInBinding.inflate(inflater, container, false)
    return binding.root
}

override fun onDestroyView() {
    super.onDestroyView()
    _binding = null
 }
}

Upvotes: 5

Sasmita Novitasari
Sasmita Novitasari

Reputation: 373

Simple and the best way

public class MainFragment extends Fragment {
    
    private FragmentMainBinding binding;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        binding = FragmentMainBinding.inflate(getLayoutInflater(), container, false);

        // binding.yourWidget.set...

        return binding.getRoot();
    }
}

Remember to always put return binding.getRoot() at the end of onCreateView()

Upvotes: 0

Eert Hoogerwerf
Eert Hoogerwerf

Reputation: 79

If you're inflating your Fragment in the constructor, view binding can be done like this:

class ExampleFragment : Fragment(R.layout.fragment_example) {

    private var binding: FragmentExampleBinding? = null

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        binding = FragmentExampleBinding.bind(view)
    }

    override fun onDestroyView() {
        binding = null
        super.onDestroyView()
    }

}

Upvotes: 7

Ronik Limbani
Ronik Limbani

Reputation: 917

You can simply do this and if you avoid mismatch view error, you can destroy the view after a move or replace the fragment.

class QuestionFragment : Fragment() {
    private var _binding: FragmentQuestionBinding? = null
    // This property is only valid between onCreateView and onDestroyView.
    private val binding get() = _binding!!

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }

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

        // Inflate the layout for this fragment
        _binding = FragmentQuestionBinding.inflate(inflater, container, false)
        val view = binding.root
        return view
    }

    override fun onDestroyView() {
        super.onDestroyView()
       _binding = null
    }
}

Upvotes: 1

Bolt UIX
Bolt UIX

Reputation: 7022

View bind in fragment using kotlin

class SignInFragment : Fragment() {

    private lateinit var bindingSignIn: SignInFragmentBinding

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        //return inflater.inflate(R.layout.sign_in_fragment, container, false)

        // Inflate the layout for this fragment
        bindingSignIn = SignInFragmentBinding.inflate(inflater, container, false)

        bindingSignIn.txtMessage.text="Sample Text"

        return bindingSignIn.root
    }

}

Upvotes: 15

chand mohd
chand mohd

Reputation: 2550

This working fine for me:

private FragmentJavaPracticeBinding binding;

@Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        binding = FragmentJavaPracticeBinding.inflate(inflater,container,false);
        return binding.getRoot();
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        binding.notesRecyclerView.setVisibility(View.VISIBLE);//this hide/show recyclerview visibility 
        Log.d("TAG", "hidden: ");
    }

Upvotes: 42

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