android studio: help RecyclerView Click does not work

Question

I'm trying to do a click event from RecyclerView in Main class, but it's not catching the click.

Interface

public interface OnItemClickListener {
    void onItemClick(int posicao);
    void onItemLongClick(int posicao);
}

interface attribute and setter

private OnItemClickListener mlistener;

public void setOnItemClickListener(OnItemClickListener listener){
    mlistener = listener;
}

class ViewHolder

public class ViewHolderArtista extends RecyclerView.ViewHolder{

    public ViewHolderArtista(@NonNull View itemView,  final OnItemClickListener listener) {
        super(itemView);

        itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(listener != null){
                    int position = getAdapterPosition();
                    if(position != RecyclerView.NO_POSITION){
                        listener.onItemClick(position);
                    }
                }
            }
        });

        itemView.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                if (listener != null){
                    int position = getAdapterPosition();
                    if (position != RecyclerView.NO_POSITION){
                        listener.onItemLongClick(position);
                    }
                }
                return true;
            }
        });
    }

}

implementing in class main:

artistaAdapter.setOnItemClickListener(new OnItemClickListener() {
    @Override
    public void onItemClick(int posicao) {
        Log.d("TESTE", "CLIQUE CURTO" +posicao);
    }

    @Override
    public void onItemLongClick(int posicao) {
        Log.d("TESTE", "CLIQUE LONGO" +posicao);
    }
});

However, nothing happens when clicking:

that is, I am implementing the click event of RecyclerView in the main class, but it is not working, it does not catch the position of the clicked item.

Answer 1

不要在构造中使用setOnClickListener，而是重写onBindViewHolder函数，在其中使用setOnClickListener

Answer 2

it will always return null because it won't initialize.

Use click listeners in the recyclerview Adapter's onBindViewHolder() method.

Answer 3

You can do as the others said by setting the listener in onBindViewHolder , or I have got a class for recyclerView actions as onClick and onLongClick .

import android.support.v7.widget.RecyclerView;
import android.view.View;

public class ItemClickSupport {
    private final RecyclerView mRecyclerView;
    private OnItemClickListener mOnItemClickListener;
    private OnItemLongClickListener mOnItemLongClickListener;
    private View.OnClickListener mOnClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (mOnItemClickListener != null) {
                // ask the RecyclerView for the viewHolder of this view.
                // then use it to get the position for the adapter
                RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
                mOnItemClickListener.onItemClicked(mRecyclerView, holder.getAdapterPosition(), v);
            }
        }
    };
    private View.OnLongClickListener mOnLongClickListener = new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            if (mOnItemLongClickListener != null) {
                RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
                return mOnItemLongClickListener.onItemLongClicked(mRecyclerView, holder.getAdapterPosition(), v);
            }
            return false;
        }
    };
    private RecyclerView.OnChildAttachStateChangeListener mAttachListener
            = new RecyclerView.OnChildAttachStateChangeListener() {
        @Override
        public void onChildViewAttachedToWindow(View view) {
            // every time a new child view is attached add click listeners to it
            if (mOnItemClickListener != null) {
                view.setOnClickListener(mOnClickListener);
            }
            if (mOnItemLongClickListener != null) {
                view.setOnLongClickListener(mOnLongClickListener);
            }
        }

        @Override
        public void onChildViewDetachedFromWindow(View view) {

        }
    };

    private ItemClickSupport(RecyclerView recyclerView) {
        mRecyclerView = recyclerView;
        // the ID must be declared in XML, used to avoid
        // replacing the ItemClickSupport without removing
        // the old one from the RecyclerView
        mRecyclerView.setTag(R.id.item_click_support, this);
        mRecyclerView.addOnChildAttachStateChangeListener(mAttachListener);
    }

    public static ItemClickSupport addTo(RecyclerView view) {
        // if there's already an ItemClickSupport attached
        // to this RecyclerView do not replace it, use it
        ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
        if (support == null) {
            support = new ItemClickSupport(view);
        }
        return support;
    }

    public static ItemClickSupport removeFrom(RecyclerView view) {
        ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
        if (support != null) {
            support.detach(view);
        }
        return support;
    }

    public ItemClickSupport setOnItemClickListener(OnItemClickListener listener) {
        mOnItemClickListener = listener;
        return this;
    }

    public ItemClickSupport setOnItemLongClickListener(OnItemLongClickListener listener) {
        mOnItemLongClickListener = listener;
        return this;
    }

    private void detach(RecyclerView view) {
        view.removeOnChildAttachStateChangeListener(mAttachListener);
        view.setTag(R.id.item_click_support, null);
    }

    public interface OnItemClickListener {

        void onItemClicked(RecyclerView recyclerView, int position, View v);
    }

    public interface OnItemLongClickListener {

        boolean onItemLongClicked(RecyclerView recyclerView, int position, View v);
    }
}  

Don't forget to import <package>.R