i have a fragment and a simple recyclerview.

recyclerview have to item , a textview and a button for each item.

i want when user clicked on plus button , the textview(counter) get increase or change , how i shoud do this?

now i just have a simple toast for button plus click.

this is my adapter:

public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.ViewHolder> {

    private List<String> mData;
    private LayoutInflater mInflater;
    private ItemClickListener mClickListener;

    // data is passed into the constructor
    MyRecyclerViewAdapter(Context context, List<String> data) {
        this.mInflater = LayoutInflater.from(context);
        this.mData = data;
    }

    // inflates the row layout from xml when needed
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = mInflater.inflate(R.layout.recyclerview_row, parent, false);
        return new ViewHolder(view);
    }

    // binds the data to the TextView in each row
    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        String animal = mData.get(position);
        holder.myTextView.setText(animal);
    }

    // total number of rows
    @Override
    public int getItemCount() {
        return mData.size();
    }


    // stores and recycles views as they are scrolled off screen
    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        TextView myTextView;
        Button plus;

        ViewHolder(View itemView) {
            super(itemView);
            myTextView = itemView.findViewById(R.id.tvAnimalName);
            plus = itemView.findViewById(R.id.buttonplus);
            itemView.setOnClickListener(this);

            plus.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {

                    Toast.makeText(itemView.getContext(), "test", Toast.LENGTH_SHORT).show();

                }

            });

        }

        @Override
        public void onClick(View view) {
            if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
        }
    }

    // convenience method for getting data at click position
    String getItem(int id) {
        return mData.get(id);
    }

    // allows clicks events to be caught
    void setClickListener(ItemClickListener itemClickListener) {
        this.mClickListener = itemClickListener;
    }

    // parent activity will implement this method to respond to click events
    public interface ItemClickListener {
        void onItemClick(View view, int position);
    }
}

and my adapter row layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:padding="10dp">

    <TextView
        android:id="@ id/tvAnimalName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"/>
    <Button
        android:id="@ id/buttonplus"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Plus"
    >

    </Button>
</LinearLayout>

and there is my fragment java:

public class FirstFragment extends Fragment implements MyRecyclerViewAdapter.ItemClickListener {
MyRecyclerViewAdapter adapter;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View v = inflater.inflate(R.layout.fragment_first, container, false);

    // data to populate the RecyclerView with
    ArrayList<String> animalNames = new ArrayList<>();
    animalNames.add("Horse");
    animalNames.add("Cow");
    animalNames.add("Camel");
    animalNames.add("Sheep");
    animalNames.add("Goat");

    // set up the RecyclerView
    RecyclerView recyclerView = v.findViewById(R.id.rvAnimals);
    recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
    adapter = new MyRecyclerViewAdapter(getContext(), animalNames);
    adapter.setClickListener(this);
    recyclerView.setAdapter(adapter);

    return v;
}

@Override
public void onItemClick(View view, int position) {
    
}
}

and my fragment layout:

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".FirstFragment">
<androidx.recyclerview.widget.RecyclerView
    android:id="@ id/rvAnimals"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

<TextView
    android:id="@ id/counter"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    android:text="1"
    >

</TextView>
</androidx.constraintlayout.widget.ConstraintLayout>

CodePudding user response：

//try this bro

//in your adapter
    int count=1;
  
    @Override
        public void onBindViewHolder(ViewHolder holder, int position) {
            String animal = mData.get(position);
            holder.myTextView.setText(animal);
            holder.plus.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
    
                    mClickListener.onItemClick(view,count) 
                    count  ;
                    }
    
                });
    }

//in your fragment
@Override
public void onItemClick(View view, int position) {
    anytextview.settext(String.valueof(position);
}