I tried to create a RecyclerView on a Fragment with a custom layout, so I used an adapter, but, when I tried to set the adapter, I got these errors:
java.lang.NullPointerException: Attempt to invoke virtual method 'void androidx.recyclerview.widget.RecyclerView.setAdapter(androidx.recyclerview.widget.RecyclerView$Adapter)' on a null object reference
I've tried some solutions on the Internet, everyone suggest to try finding the recyclerview inside the OnViewCreated. But my code still cant find the recyclerview inside the layout file.
This is my fragment_hadiah.xml File
<LinearLayout 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"
tools:context=".HadiahFragment"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:padding="20dp"
android:layout_height="wrap_content"
android:orientation="vertical">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/ic_video"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="x Dopa Eggs"
android:textSize="20sp"
android:textStyle="bold"
android:layout_marginStart="10dp"/>
</LinearLayout>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Tukarkan pointmu"/>
</LinearLayout>
<HorizontalScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="horizontal"
android:paddingVertical="10dp">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="GOPAY"
android:layout_marginLeft="20dp"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="OVO"
android:layout_marginLeft="20dp"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="DANA"
android:layout_marginLeft="20dp"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Coming Soon"
android:layout_marginLeft="20dp"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Coming Soon"
android:layout_marginLeft="20dp"/>
</LinearLayout>
</HorizontalScrollView>
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/hadiahRecylerView"/>
</LinearLayout>
Here is my HadiahFragment.java class
package com.dopami.projecthatchedeggs;
import android.os.Bundle;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import com.dopami.projecthatchedeggs.adapter.HadiahItemAdapter;
import java.util.ArrayList;
import java.util.List;
/**
* A simple {@link Fragment} subclass.
* Use the {@link HadiahFragment#newInstance} factory method to
* create an instance of this fragment.
*/
public class HadiahFragment extends Fragment {
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private String mParam1;
private String mParam2;
RecyclerView hadiahRecyclerView;
public HadiahFragment() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment HadiahFragment.
*/
public static HadiahFragment newInstance(String param1, String param2) {
HadiahFragment fragment = new HadiahFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_beranda, container, false);
return view;
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
List<String> itemList = new ArrayList<>();
for (int i = 0; i < 5; i++) {
itemList.add(String.valueOf(i));
}
Toast.makeText((HomeActivity) getActivity(), "OK", Toast.LENGTH_SHORT).show();
hadiahRecyclerView = view.findViewById(R.id.hadiahRecylerView);
HadiahItemAdapter itemAdapter = new HadiahItemAdapter(itemList, (HomeActivity) getActivity());
GridLayoutManager gridLayoutManager = new GridLayoutManager((HomeActivity)getActivity(), 2);
hadiahRecyclerView.setAdapter(itemAdapter);
hadiahRecyclerView.setLayoutManager(gridLayoutManager);
}
}
Here is My HadiahItemAdapter.java Class
package com.dopami.projecthatchedeggs.adapter;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.cardview.widget.CardView;
import androidx.recyclerview.widget.RecyclerView;
import com.dopami.projecthatchedeggs.R;
import java.util.List;
public class HadiahItemAdapter extends RecyclerView.Adapter<HadiahItemAdapter.ItemViewHolder>{
private List<String> mItemList;
private Context mContext;
public HadiahItemAdapter(List<String> mItemList, Context mContext) {
this.mItemList = mItemList;
this.mContext = mContext;
}
@NonNull
@Override
public ItemViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.hadiah_card_item, parent, false);
return new ItemViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull ItemViewHolder holder, int position) {
String item = mItemList.get(position);
holder.textView.setText(item);
}
@Override
public int getItemCount() {
return mItemList.size();
}
class ItemViewHolder extends RecyclerView.ViewHolder{
private CardView cardView;
private TextView textView;
public ItemViewHolder(@NonNull View itemView) {
super(itemView);
cardView = itemView.findViewById(R.id.hadiahCardView);
textView = itemView.findViewById(R.id.hadiahCardTextView);
}
}
}
Looking forward to the solutions from you guys, thanks for helping...
