为什么 RecyclerView 没有 onItemClickListener()?

我在浏览RecyclerView很惊讶地看到RecyclerView没有onItemClickListener()

我有两个问题。

主要问题

我想知道为什么 Google 删除了onItemClickListener()吗?

是否存在性能问题或其他问题?

次要问题

我通过在RecyclerView.Adapter编写onClick解决了我的问题:

public static class ViewHolder extends RecyclerView.ViewHolder implements OnClickListener {

    public TextView txtViewTitle;
    public ImageView imgViewIcon;

    public ViewHolder(View itemLayoutView) {
        super(itemLayoutView);
        txtViewTitle = (TextView) itemLayoutView.findViewById(R.id.item_title);
        imgViewIcon = (ImageView) itemLayoutView.findViewById(R.id.item_icon);
    }

    @Override
    public void onClick(View v) {

    }
}

这样可以 / 有更好的方法吗?

答案

public class ReactiveAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
    String[] mDataset = { "Data", "In", "Adapter" };

    private final PublishSubject<String> onClickSubject = PublishSubject.create();

    @Override 
    public void onBindViewHolder(final ViewHolder holder, int position) {
        final String element = mDataset[position];

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

    public Observable<String> getPositionClicks(){
        return onClickSubject.asObservable();
    }
}
public static class ViewHolder extends RecyclerView.ViewHolder implements OnClickListener {

    public TextView txtViewTitle;
    public ImageView imgViewIcon;
    public IMyViewHolderClicks mListener;

    public ViewHolder(View itemLayoutView, IMyViewHolderClicks listener) {
        super(itemLayoutView);
        mListener = listener;
        txtViewTitle = (TextView) itemLayoutView.findViewById(R.id.item_title);
        imgViewIcon = (ImageView) itemLayoutView.findViewById(R.id.item_icon);
        imgViewIcon.setOnClickListener(this);
        itemLayoutView.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        if (v instanceof ImageView){
           mListener.onTomato((ImageView)v);
        } else {
           mListener.onPotato(v);
        }
    }

    public static interface IMyViewHolderClicks {
        public void onPotato(View caller);
        public void onTomato(ImageView callerImage);
    }

}
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {

   String[] mDataset = { "Data" };

   @Override
   public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
       View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.my_layout, parent, false);

       MyAdapter.ViewHolder vh = new ViewHolder(v, new MyAdapter.ViewHolder.IMyViewHolderClicks() { 
           public void onPotato(View caller) { Log.d("VEGETABLES", "Poh-tah-tos"); };
           public void onTomato(ImageView callerImage) { Log.d("VEGETABLES", "To-m8-tohs"); }
        });
        return vh;
    }

    // Replace the contents of a view (invoked by the layout manager) 
    @Override 
    public void onBindViewHolder(ViewHolder holder, int position) {
        // Get element from your dataset at this position 
        // Replace the contents of the view with that element 
        // Clear the ones that won't be used
        holder.txtViewTitle.setText(mDataset[position]);
    } 

    // Return the size of your dataset (invoked by the layout manager) 
    @Override 
    public int getItemCount() { 
        return mDataset.length;
    } 
  ...
recyclerView.onItemClick { recyclerView, position, v ->
    // do it
}
typealias OnRecyclerViewItemClickListener = (recyclerView: RecyclerView, position: Int, v: View) -> Unit
typealias OnRecyclerViewItemLongClickListener = (recyclerView: RecyclerView, position: Int, v: View) -> Boolean

class ItemClickSupport(private val recyclerView: RecyclerView) {

    private var onItemClickListener: OnRecyclerViewItemClickListener? = null
    private var onItemLongClickListener: OnRecyclerViewItemLongClickListener? = null

    private val attachListener: RecyclerView.OnChildAttachStateChangeListener by lazy {
        object : RecyclerView.OnChildAttachStateChangeListener {
            override fun onChildViewAttachedToWindow(view: View) {
                // every time a new child view is attached add click listeners to it
                val holder = this@ItemClickSupport.recyclerView.getChildViewHolder(view)
                        .takeIf { it is ItemClickSupportViewHolder } as? ItemClickSupportViewHolder

                if (onItemClickListener != null && holder?.isClickable != false) {
                    view.setOnClickListener(onClickListener)
                }
                if (onItemLongClickListener != null && holder?.isLongClickable != false) {
                    view.setOnLongClickListener(onLongClickListener)
                }
            }

            override fun onChildViewDetachedFromWindow(view: View) {

            }
        }
    }

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

    companion object {
        fun addTo(view: RecyclerView): ItemClickSupport {
            // if there's already an ItemClickSupport attached
            // to this RecyclerView do not replace it, use it
            var support: ItemClickSupport? = view.getTag(R.id.item_click_support) as? ItemClickSupport
            if (support == null) {
                support = ItemClickSupport(view)
            }
            return support
        }

        fun removeFrom(view: RecyclerView): ItemClickSupport? {
            val support = view.getTag(R.id.item_click_support) as? ItemClickSupport
            support?.detach(view)
            return support
        }
    }

    private val onClickListener = View.OnClickListener { v ->
        val listener = onItemClickListener ?: return@OnClickListener
        // ask the RecyclerView for the viewHolder of this view.
        // then use it to get the position for the adapter
        val holder = this.recyclerView.getChildViewHolder(v)
        listener.invoke(this.recyclerView, holder.adapterPosition, v)
    }

    private val onLongClickListener = View.OnLongClickListener { v ->
        val listener = onItemLongClickListener ?: return@OnLongClickListener false
        val holder = this.recyclerView.getChildViewHolder(v)
        return@OnLongClickListener listener.invoke(this.recyclerView, holder.adapterPosition, v)
    }

    private fun detach(view: RecyclerView) {
        view.removeOnChildAttachStateChangeListener(attachListener)
        view.setTag(R.id.item_click_support, null)
    }

    fun onItemClick(listener: OnRecyclerViewItemClickListener?): ItemClickSupport {
        onItemClickListener = listener
        return this
    }

    fun onItemLongClick(listener: OnRecyclerViewItemLongClickListener?): ItemClickSupport {
        onItemLongClickListener = listener
        return this
    }

}

/** Give click-ability and long-click-ability control to the ViewHolder */
interface ItemClickSupportViewHolder {
    val isClickable: Boolean get() = true
    val isLongClickable: Boolean get() = true
}

// Extension function
fun RecyclerView.addItemClickSupport(configuration: ItemClickSupport.() -> Unit = {}) = ItemClickSupport.addTo(this).apply(configuration)

fun RecyclerView.removeItemClickSupport() = ItemClickSupport.removeFrom(this)

fun RecyclerView.onItemClick(onClick: OnRecyclerViewItemClickListener) {
    addItemClickSupport { onItemClick(onClick) }
}
fun RecyclerView.onItemLongClick(onLongClick: OnRecyclerViewItemLongClickListener) {
    addItemClickSupport { onItemLongClick(onLongClick) }
}
class MyViewHolder(view): RecyclerView.ViewHolder(view), ItemClickSupportViewHolder {
    override val isClickable: Boolean get() = false
    override val isLongClickable: Boolean get() = false
}
ItemClickSupport.addTo(mRecyclerView)
        .setOnItemClickListener(new ItemClickSupport.OnItemClickListener() {
    @Override
    public void onItemClicked(RecyclerView recyclerView, int position, View v) {
        // do it
    }
});
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);
    }
}
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <item name="item_click_support" type="id" />
</resources>
public Adapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.view_image_and_text, parent, false);
v.setOnClickListener(new MyOnClickListener());
class MyOnClickListener implements View.OnClickListener {
    @Override
    public void onClick(View v) {
       int itemPosition = recyclerView.indexOfChild(v);
       Log.e("Clicked and Position is ",String.valueOf(itemPosition));
    }
}
public class RecyclerItemClickListener implements RecyclerView.OnItemTouchListener {

private OnItemClickListener mListener;
public interface OnItemClickListener {
    public void onItemClick(View view, int position);
}
GestureDetector mGestureDetector;
public RecyclerItemClickListener(Context context, OnItemClickListener listener) {
    mListener = listener;
    mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            return true;
        }
    });
}
@Override
public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e) {
    View childView = view.findChildViewUnder(e.getX(), e.getY());
    if (childView != null && mListener != null && mGestureDetector.onTouchEvent(e)) {
        mListener.onItemClick(childView, view.getChildAdapterPosition(childView));
    }
    return false;
}

@Override
public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) {
}

@Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {

  }
}
recyclerView = (RecyclerView)rootView. findViewById(R.id.recyclerView);
    RecyclerView.LayoutManager mLayoutManager = new            LinearLayoutManager(getActivity());
    recyclerView.setLayoutManager(mLayoutManager);
    recyclerView.addOnItemTouchListener(
            new RecyclerItemClickListener(getActivity(), new   RecyclerItemClickListener.OnItemClickListener() {
                @Override
                public void onItemClick(View view, int position) {
                    // TODO Handle item click
                    Log.e("@@@@@",""+position);
                }
            })
    );
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder>{

private LayoutInflater layoutInflater;
private List<MyObject> items;
private AdapterView.OnItemClickListener onItemClickListener;

public MyAdapter(Context context, AdapterView.OnItemClickListener onItemClickListener, List<MyObject> items) {
    layoutInflater = LayoutInflater.from(context);
    this.items = items;
    this.onItemClickListener = onItemClickListener;
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = layoutInflater.inflate(R.layout.my_row_layout, parent, false);
    return new ViewHolder(view);
}

@Override
public void onBindViewHolder(ViewHolder holder, int position) {
    MyObject item = items.get(position);
}

public MyObject getItem(int position) {
    return items.get(position);
}


class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    private TextView title;
    private ImageView avatar;

    public ViewHolder(View itemView) {
        super(itemView);
        title = itemView.findViewById(R.id.title);
        avatar = itemView.findViewById(R.id.avatar);

        title.setOnClickListener(this);
        avatar.setOnClickListener(this);
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        //passing the clicked position to the parent class
        onItemClickListener.onItemClick(null, view, getAdapterPosition(), view.getId());
    }
}
}
public class MyFragment extends Fragment implements AdapterView.OnItemClickListener {

private RecyclerView recycleview;
private MyAdapter adapter;

    .
    .
    .

private void init(Context context) {
    //passing this fragment as OnItemClickListener to the adapter
    adapter = new MyAdapter(context, this, items);
    recycleview.setAdapter(adapter);
}

@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
    //you can get the clicked item from the adapter using its position
    MyObject item = adapter.getItem(position);

    //you can also find out which view was clicked
    switch (view.getId()) {
        case R.id.title:
            //title view was clicked
            break;
        case R.id.avatar:
            //avatar view was clicked
            break;
        default:
            //the whole row was clicked
    }
}

}
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.users_list);            
UsersAdapter adapter = new UsersAdapter(users, this);
recyclerView.setAdapter(adapter);
adapter.setOnCardClickListner(this);
public class UsersAdapter extends RecyclerView.Adapter<UsersAdapter.UserViewHolder> {
        private ArrayList<User> mDataSet;
        OnCardClickListner onCardClickListner;


        public UsersAdapter(ArrayList<User> mDataSet) {
            this.mDataSet = mDataSet;
        }

        @Override
        public UserViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.user_row_layout, parent, false);
            UserViewHolder userViewHolder = new UserViewHolder(v);
            return userViewHolder;
        }

        @Override
        public void onBindViewHolder(UserViewHolder holder, final int position) {
            holder.name_entry.setText(mDataSet.get(position).getUser_name());
            holder.cardView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    onCardClickListner.OnCardClicked(v, position);
                }
            });
        }

        @Override
        public int getItemCount() {
            return mDataSet.size();
        }

        @Override
        public void onAttachedToRecyclerView(RecyclerView recyclerView) {
            super.onAttachedToRecyclerView(recyclerView);
        }


        public static class UserViewHolder extends RecyclerView.ViewHolder {
            CardView cardView;
            TextView name_entry;

            public UserViewHolder(View itemView) {
                super(itemView);
                cardView = (CardView) itemView.findViewById(R.id.user_layout);
                name_entry = (TextView) itemView.findViewById(R.id.name_entry);
             }
        }

        public interface OnCardClickListner {
            void OnCardClicked(View view, int position);
        }

        public void setOnCardClickListner(OnCardClickListner onCardClickListner) {
            this.onCardClickListner = onCardClickListner;
        }
    }
@Override
    public void OnCardClicked(View view, int position) {
        Log.d("OnClick", "Card Position" + position);
    }
LinearLayoutManager llm = new LinearLayoutManager(context);
llm.setOrientation(LinearLayoutManager.HORIZONTAL);
recyclerView.setLayoutManager(llm);
Consumer<String> mClickConsumer = new Consumer<String>() {
        @Override
        public void accept(@NonNull String element) throws Exception {
            Toast.makeText(getApplicationContext(), element +" was clicked", Toast.LENGTH_LONG).show();
        }
    };

ReactiveAdapter rxAdapter = new ReactiveAdapter();
rxAdapter.getPositionClicks().subscribe(mClickConsumer);
public Observable<String> getPositionClicks(){
    return onClickSubject;
}

如何将所有示例放在一起...

  • onClick()处理
  • 光标 - RecyclerView
  • ViewHolder 类型

    public class OrderListCursorAdapter extends CursorRecyclerViewAdapter<OrderListCursorAdapter.ViewHolder> {
    
    private static final String TAG = OrderListCursorAdapter.class.getSimpleName();
    private static final int ID_VIEW_HOLDER_ACTUAL = 0;
    private static final int ID_VIEW_HOLDER = 1;
    
    public OrderListCursorAdapter(Context context, Cursor cursor) {
        super(context, cursor);
    }
    
    public static class ViewHolderActual extends ViewHolder {
        private static final String TAG = ViewHolderActual.class.getSimpleName();
        protected IViewHolderClick listener;
        protected Button button;
    
        public ViewHolderActual(View v, IViewHolderClick listener) {
            super(v, listener);
            this.listener = listener;
            button = (Button) v.findViewById(R.id.orderList_item_button);
            button.setOnClickListener(this);
        }
    
        public void initFromData(OrderData data) {
            Log.d(TAG, "><initFromData(data=" + data + ")");
            orderId = data.getId();
            vAddressStart.setText(data.getAddressStart());
            vAddressEnd.setText(data.getAddressEnd());
        }
    
        @Override
        public void onClick(View view) {
            if (view instanceof Button) {
                listener.onButtonClick((Button) view, getPosition(), this);
            } else {
                super.onClick(view);
            }
        }
    
        public interface IViewHolderClick extends ViewHolder.IViewHolderClick {
            public void onButtonClick(Button button, int position, ViewHolder viewHolder);
        }
    }
    
    public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        private static final String TAG = ViewHolder.class.getSimpleName();
        protected long orderId;
        protected IViewHolderClick listener;
        protected TextView vAddressStart;
        protected TextView vAddressEnd;
        protected TextView vStatus;
    
        public ViewHolder(View v, IViewHolderClick listener) {
            super(v);
            this.listener = listener;
            v.setOnClickListener(this);
    
            vAddressStart = (TextView) v.findViewById(R.id.addressStart);
            vAddressEnd = (TextView) v.findViewById(R.id.addressEnd);
            vStatus = (TextView) v.findViewById(R.id.status);
        }
    
        public void initFromData(OrderData data) {
            Log.d(TAG, "><initFromData(data=" + data + ")");
            orderId = data.getId();
            vAddressStart.setText(data.getAddressStart());
            vAddressEnd.setText(data.getAddressEnd());
        }
    
        public long getOrderId() {
            return orderId;
        }
    
        @Override
        public void onClick(View view) {
            listener.onCardClick(view, getPosition(), this);
        }
    
        public interface IViewHolderClick {
            public void onCardClick(View view, int position, ViewHolder viewHolder);
        }
    }
    
    @Override
    public int getItemViewType(int position) {
        return position == 0 ? ID_VIEW_HOLDER_ACTUAL : ID_VIEW_HOLDER;
    }
    
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        Log.d(TAG, ">>onCreateViewHolder(parent=" + parent + ", viewType=" + viewType + ")");
    
        ViewHolder result;
    
        switch (viewType) {
            case ID_VIEW_HOLDER_ACTUAL: {
                View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_layout_actual, parent, false);
                result = new ViewHolderActual(itemView, new ViewHolderActual.IViewHolderClick() {
                    @Override
                    public void onCardClick(View view, int position, ViewHolder viewHolder) {
                        Log.d(TAG, "><onCardClick(view=" + view + ", position=" + position + ", viewHolder=" + viewHolder + ")");
                        Intent intent = new Intent(view.getContext(), OrderDetailActivity.class);
                        intent.putExtra(OrderDetailActivity.ARG_ORDER_ID, viewHolder.getOrderId());
                        view.getContext().startActivity(intent);
                    }
    
                    @Override
                    public void onButtonClick(Button button, int position, ViewHolder viewHolder) {
                        Log.d(TAG, "><onButtonClick(button=" + button + ", position=" + position + ", viewHolder=" + viewHolder + ")");
                        Intent intent = new Intent(button.getContext(), OrderMapActivity.class);
                        intent.putExtra(OrderMapActivity.ARG_ORDER_ID, viewHolder.getOrderId());
                        button.getContext().startActivity(intent);
                    }
                });
                break;
            }
            case ID_VIEW_HOLDER:
            default: {
                View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_layout, parent, false);
                result = new ViewHolder(itemView, new ViewHolder.IViewHolderClick() {
                    @Override
                    public void onCardClick(View view, int position, ViewHolder viewHolder) {
                        Log.d(TAG, "><onCardClick(view=" + view + ", position=" + position + ", viewHolder=" + viewHolder + ")");
                        Intent intent = new Intent(view.getContext(), OrderDetailActivity.class);
                        intent.putExtra(OrderDetailActivity.ARG_ORDER_ID, viewHolder.getOrderId());
                        view.getContext().startActivity(intent);
                    }
                });
                break;
            }
        }
    
        Log.d(TAG, "<<onCreateViewHolder(parent=" + parent + ", viewType=" + viewType + ")= " + result);
        return result;
    }
    
    @Override
    public void onBindViewHolder(ViewHolder viewHolder, Cursor cursor) {
        Log.d(TAG, "><onBindViewHolder(viewHolder=" + viewHolder + ", cursor=" + cursor + ")");
        final OrderData orderData = new OrderData(cursor);
        viewHolder.initFromData(orderData);
    }
    }
class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
    private ImageView image;
    private TextView title;
    private TextView price;

    public MyViewHolder(View itemView) {
        super(itemView);
        image = (ImageView)itemView.findViewById(R.id.horizontal_list_image);
        title = (TextView)itemView.findViewById(R.id.horizontal_list_title);
        price = (TextView)itemView.findViewById(R.id.horizontal_list_price);
        image.setOnClickListener(this);
        title.setOnClickListener(this);
        price.setOnClickListener(this);
    }


    @Override
    public void onClick(View v) {
        Toast.makeText(context, "Item click nr: "+getLayoutPosition(), Toast.LENGTH_SHORT).show();
    }
}