我正在探索RecyclerView,我很惊讶地看到,RecyclerView没有onItemClickListener()。

我有两个问题。

主要问题

我想知道为什么谷歌删除onItemClickListener()?

是否存在性能问题或其他问题?

次要的问题

我解决了我的问题写onClick在我的RecyclerView。适配器:

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) {

    }
}

这样可以吗/有更好的办法吗?


当前回答

跟进MLProgrammer-CiM的优秀RxJava解决方案

消费/观察点击

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);

RxJava 2.+

将原tl;dr修改为:

public Observable<String> getPositionClicks(){
    return onClickSubject;
}

PublishSubject#asObservable()被移除。只需要返回PublishSubject,它是一个可观察对象。

其他回答

是的,你可以

public ViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {

    //inflate the view 

    View view = LayoutInflator.from(parent.getContext()).inflate(R.layout.layoutID,null);

    ViewHolder holder = new ViewHolder(view);

    //here we can set onClicklistener
    view.setOnClickListener(new  View.OnClickListeener(){
        public void onClick(View v)
        {
            //action
        }
    });

return holder;

Android Recyclerview与onItemClickListener, 为什么我们不能尝试这是工作像ListView。

来源:Link

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) {

  }
}

并设置这个为RecyclerView:

    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);
                }
            })
    );

Recyclerview动画没有经过测试,其他正常。我认为它已经优化到最大。接口有其他用途,可以暂时忽略。

public abstract class BaseAdapterRV<VH extends BaseViewHolder> extends RecyclerView.Adapter<VH> implements AdapterInterface {
    public final String TAG = getClass().getSimpleName();

    protected final Activity mActivity;
    protected final LayoutInflater mInflater;
    protected ItemClickInterface<?, Integer> mListener;

    public BaseAdapterRV(Activity activity) {
        mActivity = activity;
        mInflater = LayoutInflater.from(mActivity);
    }

    @Override
    public final VH onCreateViewHolder(ViewGroup parent, int viewType) {
        return onCreateViewHolder(parent, viewType, mInflater);
    }

    @Override
    public final void onBindViewHolder(VH holder, int position) {
        holder.itemView.setTag(R.id.tag_view_click, position);
        //创建点击事件
        holder.itemView.setOnClickListener(mListener);
        holder.itemView.setOnLongClickListener(mListener);
        onBindVH(holder, position);
    }


    ///////////////////////////////////////////////////////////////////////////
    // 以下是增加的方法
    ///////////////////////////////////////////////////////////////////////////

    /**
     * 注意!涉及到notifyItemInserted刷新时立即获取position可能会不正确
     * 里面也有onItemLongClick
     */
    public void setOnItemClickListener(ItemClickInterface<?, Integer> listener) {
        mListener = listener;
        notifyDataSetChanged();
    }

    @NonNull
    protected abstract VH onCreateViewHolder(ViewGroup parent, int viewType, LayoutInflater inflater);

    protected abstract void onBindVH(VH holder, int position);

}

这是接口

/**
 * OnItemClickListener的接口
 * 见子类实现{@link OnItemClickListener}{@link OnItemItemClickListener}
 */
public interface ItemClickInterface<DATA1, DATA2> extends View.OnClickListener, View.OnLongClickListener {

    void onItemClick(DATA1 data1, DATA2 data2);

    boolean onItemLongClick(DATA1 data1, DATA2 data2);
}

这是一个抽象类

public abstract class OnItemClickListener<DATA> implements ItemClickInterface<View, DATA> {
    @Override
    public void onClick(View v) {
        onItemClick(v, (DATA) v.getTag(R.id.tag_view_click));
    }

    @Override
    public boolean onLongClick(View v) {
        return onItemLongClick(v, (DATA) v.getTag(R.id.tag_view_click));
    }

    @Override
    public boolean onItemLongClick(View view, DATA data) {
        return false;
    }
}

你只需要它

    mAdapter.setOnItemClickListener(new OnItemClickListener<Integer>() {
        @Override
        public void onItemClick(View view, Integer integer) {

        }

        @Override
        public boolean onItemLongClick(View view, Integer integer) {
            return true;
        }
    });

使用RxJava和PublishSubject为点击公开一个Observable。

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();
    }
}

原来的帖子:

自从ListView的引入,onItemClickListener就一直存在问题。当你有一个内部元素的点击监听器时,回调不会被触发,但它没有被通知或良好的记录(如果有的话),所以有很多困惑和so问题。

考虑到RecyclerView更进一步,没有行/列的概念,而是任意布局的子节点数量,他们将onClick委托给每个子节点,或者委托给程序员实现。

不要认为Recyclerview是ListView的1:1替代品,而是一个更灵活的组件,用于复杂的用例。正如你所说,你的解决方案是谷歌对你的期望。现在您有了一个适配器,它可以将onClick委托给传递给构造函数的接口,这对于ListView和Recyclerview来说都是正确的模式。

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);
    }

}

然后在适配器上

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;
    } 
  ...

Now look into that last piece of code: onCreateViewHolder(ViewGroup parent, int viewType) the signature already suggest different view types. For each one of them you'll require a different viewholder too, and subsequently each one of them can have a different set of clicks. Or you can just create a generic viewholder that takes any view and one onClickListener and applies accordingly. Or delegate up one level to the orchestrator so several fragments/activities have the same list with different click behaviour. Again, all flexibility is on your side.

它是一个非常需要的组件,非常接近我们的内部实现和到目前为止对ListView的改进。谷歌终于承认了这一点,这很好。

如何把它们放在一起举例…

onClick() handling Cursor - RecyclerView ViewHolder types 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); } }