how to set onclicklistener with int array in recyclerview for cardview android

Question

I want to click on Cardview items and intent to another activities using if else statements. Please help.

MainActivity.java

public class MainActivity extends AppCompatActivity {

private RecyclerView imagesRV;
private int[] images = {R.drawable.image01, R.drawable.image02, R.drawable.image03, R.drawable.image04, R.drawable.image05, R.drawable.image06, R.drawable.image07, R.drawable.image08};
private RecyclerViewAdapter imageAdapter;
//private ArrayList<String> imagePaths;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home_page);


    imagesRV = (RecyclerView) findViewById(R.id.idRVImages);

    prepareRecyclerView();
}

private void prepareRecyclerView() {
    imageAdapter = new RecyclerViewAdapter(MainActivity.this, images);

    GridLayoutManager manager = new GridLayoutManager(MainActivity.this, 2);

    imagesRV.setLayoutManager(manager);
    imagesRV.setAdapter(imageAdapter);
}

}

RecyclerViewAdapter.java

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.RecyclerViewHolder> {

private final Context context;
private final int[] imagePathArrayList;

public RecyclerViewAdapter(Context context, int[] imagePathArrayList) {
    this.context = context;
    this.imagePathArrayList = imagePathArrayList;
}

@NonNull
@Override
public RecyclerViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.cardview, parent, false);

    return  new RecyclerViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull RecyclerViewHolder holder, int position) {
    int imageId = imagePathArrayList[position];

        Picasso.get().load(imageId).placeholder(R.drawable.ic_launcher_background).into(holder.imageIV);

        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                    
            }
        });
        
}

@Override
public int getItemCount() {
    return imagePathArrayList.length;
}

public static class RecyclerViewHolder extends RecyclerView.ViewHolder {

    private final ImageView imageIV;

    public RecyclerViewHolder(@NonNull View itemView) {
        super(itemView);

        imageIV = itemView.findViewById(R.id.idIVImage);
    }
}

}

Answer 1

1. Create interface:

    public interface MyOnClick {
        void onClick(int imageId);
    }
   

2. Add a reference to MyOnClick to the constructor

   public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.RecyclerViewHolder> {
       ...
       private final MyOnClick myOnClick;
   
       public RecyclerViewAdapter(Context context, int[] imagePathArrayList, MyOnClick myOnClick) {
           this.context = context;
           this.imagePathArrayList = imagePathArrayList;
           this.myOnClick = myOnClick
       }
       ...
       @Override
       public void onBindViewHolder(@NonNull RecyclerViewHolder holder, int position) {
           final int imageId = imagePathArrayList[position];
           Picasso.get().load(imageId).placeholder(R.drawable.ic_launcher_background).into(holder.imageIV);
   
           holder.itemView.setOnClickListener(new View.OnClickListener() {
               @Override
               public void onClick(View v) {
                   myOnClick.onClick(imageId)
               }
           });
       }
   

3. Pass MyOnClick to adapter

    public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.RecyclerViewHolder> {
        private RecyclerView imagesRV;
        private int[] images = {R.drawable.image01, R.drawable.image02, R.drawable.image03, R.drawable.image04, R.drawable.image05, R.drawable.image06, R.drawable.image07, R.drawable.image08};
        private RecyclerViewAdapter imageAdapter;
        //private ArrayList<String> imagePaths;
   
        @Override
        protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.activity_home_page);
           imagesRV = (RecyclerView) findViewById(R.id.idRVImages);
           prepareRecyclerView();
        }
   
        private void prepareRecyclerView() {
            imageAdapter = new RecyclerViewAdapter(this, images, new MyOnClick() {
                @Override
                public void onClick(int imageId) {
                    // Your action
                }
            });
   
            GridLayoutManager manager = new GridLayoutManager(MainActivity.this, 2);
   
            imagesRV.setLayoutManager(manager);
            imagesRV.setAdapter(imageAdapter);
        }
    }