How can I make click event on CardView Item from RecyclerView

Question

I referenced Simple Android RecyclerView example for make click events on items from Recyclerview. And then I apply this way to CardView from Recyclerview but I failed.

OnClick event on ViewHolder doesn't work. It looks like codes are almost same. I don't know what is the problem.

I just copied codes from the Simple Android RecyclerView example

And then changed ArrayList to ArrayList Also, I replace xml which contains textview code with cardview.

I succeeded the event when I put onClickListener on onBindViewHolder. But I heard it makes app heavier. So I want to avoid this way.

MainActivity.java

public class MainActivity extends AppCompatActivity implements MyAdapter.ItemClickListener{

    RecyclerView mRecyclerView;
    MyAdapter mAdapter;
    RecyclerView.LayoutManager mLayoutManager;
    ArrayList<MyData> myDataset;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);

        // use this setting to improve performance if you know that changes
        // in content do not change the layout size of the RecyclerView
        mRecyclerView.setHasFixedSize(true);

        // use a linear layout manager
        mLayoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(mLayoutManager);

        myDataset = new ArrayList<>();
        myDataset.add(new MyData("#InsideOut", R.drawable.a));
        myDataset.add(new MyData("#Mini", R.drawable.b));
        myDataset.add(new MyData("#ToyStroy", R.drawable.c));

        mAdapter = new MyAdapter(this, myDataset);
        mAdapter.setClickListener(this);
        mRecyclerView.setAdapter(mAdapter);
    }
    @Override
    public void onItemClick(View view, int position) {
        Toast.makeText(this, "You clicked " + mAdapter.getItem(position) + " on row number " + position, Toast.LENGTH_SHORT).show();
    }
}

MyAdapter.java

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
    private ArrayList<MyData> mDataset;
    private LayoutInflater mInflater;

    private ItemClickListener mClickListener;


    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
        // each data item is just a string in this case
        public ImageView mImageView;
        public TextView mTextView;
        public CardView cv;

        public ViewHolder(View view) {
            super(view);
            mImageView = (ImageView)view.findViewById(R.id.image);
            mTextView = (TextView)view.findViewById(R.id.textview);
            cv = (CardView)view.findViewById(R.id.cardview);
            view.setOnClickListener(this);
        }

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

    // Provide a suitable constructor (depends on the kind of dataset)
    public MyAdapter(Context context, ArrayList<MyData> myDataset) {
        this.mDataset = myDataset;
        this.mInflater = LayoutInflater.from(context);
    }

    // Create new views (invoked by the layout manager)
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = mInflater.inflate(R.layout.item_cardview, parent, false);
        return new ViewHolder(v);
    }

    // Replace the contents of a view (invoked by the layout manager)
    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        // - get element from your dataset at this position
        // - replace the contents of the view with that element
        Log.d("position", position+"");

        holder.mTextView.setText(mDataset.get(position).text);
        holder.mImageView.setImageResource(mDataset.get(position).img);

    }

    // Return the size of your dataset (invoked by the layout manager)
    @Override
    public int getItemCount() {
        return mDataset.size();
    }
    MyData getItem(int id) {
        return mDataset.get(id);
    }

    void setClickListener(ItemClickListener itemClickListener) {
        this.mClickListener = itemClickListener;
    }
    public interface ItemClickListener {
        void onItemClick(View view, int position);
    }
}

class MyData{
    public String text;
    public int img;
    public MyData(String text, int img){
        this.text = text;
        this.img = img;
    }
}

You want to enable action on clicking the whole cardview Or any particular view inside the cardview? @snail — Brahma Datta, Apr 22 '19 at 08:09
@g.brahma Datta um.. if u don't mind, I want to know either way. but the original is th whole cardview — snail, Apr 22 '19 at 22:54

score 2 · Accepted Answer · answered Apr 22 '19 at 08:30

There is also a way to do this

 public ViewHolder(final View view) {
        super(view);
        mImageView = (ImageView)view.findViewById(R.id.image);
        mTextView = (TextView)view.findViewById(R.id.textview);
        cv = (CardView)view.findViewById(R.id.cardview);

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

I take this as a solution. But I still want to know why my code does't work. thx for the answr. — snail, Apr 23 '19 at 00:51

score 2 · Answer 2 · answered Apr 23 '19 at 07:47

The problem is your interface is the part of the adapter class while your onclicklistener is part of the holder class. You need to call the clicklistener from the adapter onBindViewHolder.For that purpose you have to give the id to the root layout of the itemholder layout file, and find view by id in itemholder constructor.After that you can call clicklistener as below.

 @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        // - get element from your dataset at this position
        // - replace the contents of the view with that element
        Log.d("position", position+"");

        holder.mTextView.setText(mDataset.get(position).text);
        holder.mImageView.setImageResource(mDataset.get(position).img);
        holder.view.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mClickListener.onItemClick(v, position)
        }
    });
    }

OnclickListener in onBindViewHolder is bad practice @Raza. – Brahma Datta Apr 23 '19 at 08:44 — Brahma Datta, Apr 23 '19 at 08:44

score 1 · Answer 3 · edited Apr 27 '19 at 14:43

public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
    // each data item is just a string in this case
    public ImageView mImageView;
    public TextView mTextView;
    public CardView cv;

    public ViewHolder(View view) {
        super(view);
        mImageView = (ImageView)view.findViewById(R.id.image);
        mTextView = (TextView)view.findViewById(R.id.textview);
        cv = (CardView)view.findViewById(R.id.cardview);

      //for whole cardview (If you want to click only card)
      view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //Do the action.
            }
        });

    //if you want to click the only particular item in the CardView
    mImageView .setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               //Do the action.
            }
        });

    }
}

Try this snippet and let me know. I can solve it for you if it doesn't work.

How can I make click event on CardView Item from RecyclerView

3 Answers3