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

在阅读了@MLProgrammer-CiM的回答后,以下是我的代码:

class NormalViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{

    @Bind(R.id.card_item_normal)
    CardView cardView;

    public NormalViewHolder(View itemView) {
        super(itemView);
        ButterKnife.bind(this, itemView);
        cardView.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        if(v instanceof CardView) {
            // use getAdapterPosition() instead of getLayoutPosition()
            int itemPosition = getAdapterPosition();
            removeItem(itemPosition);
        }
    }
}

其他回答

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);
                }
            })
    );

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); } }

这招对我很管用:

@Override
public void onBindViewHolder(PlacesListViewAdapter.ViewHolder holder, int position) {
    ----
    ----
    ----
    // Set setOnClickListener(holder);
}


@Override
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

    ----
    ----
    ----

    @Override
    public void onClick(View view) {
        // Use to get the item clicked getAdapterPosition()
    }
}

RecyclerView没有一个onItemClickListener,因为RecyclerView负责回收视图(惊讶!),所以回收视图的责任是处理它接收到的点击事件。

这实际上使它更容易使用,特别是如果你有可以在多个地方点击的项目。


无论如何,检测点击一个RecyclerView项目是非常容易的。你所需要做的就是定义一个接口(如果你不使用Kotlin,在这种情况下你只需要传入一个lambda):

public class MyAdapter extends RecyclerView.Adapter<MyViewHolder> {
    private final Clicks clicks;

    public MyAdapter(Clicks clicks) {
        this.clicks = clicks;
    }

    private List<MyObject> items = Collections.emptyList();

    public void updateData(List<MyObject> items) {
        this.items = items;
        notifyDataSetChanged(); // TODO: use ListAdapter for diffing instead if you need animations
    }

    public interface Clicks {
        void onItemSelected(MyObject myObject, int position);
    }

    public class MyViewHolder extends RecyclerView.ViewHolder {
        private MyObject myObject;    

        public MyViewHolder(View view) {
            super(view);
            // bind views
            view.setOnClickListener((v) -> {
                int adapterPosition = getBindingAdapterPosition();
                if(adapterPosition >= 0) {
                    clicks.onItemSelected(myObject, adapterPosition);
                }
            });
        }

        public void bind(MyObject myObject) {
            this.myObject = myObject;
            // bind data to views
        }
    }
}

Kotlin中的代码相同:

class MyAdapter(val itemClicks: (MyObject, Int) -> Unit): RecyclerView.Adapter<MyViewHolder>() {
    private var items: List<MyObject> = Collections.emptyList()

    fun updateData(items: List<MyObject>) {
        this.items = items
        notifyDataSetChanged() // TODO: use ListAdapter for diffing instead if you need animations
    }

    inner class MyViewHolder(val myView: View): RecyclerView.ViewHolder(myView) {
        private lateinit var myObject: MyObject

        init {
            // binds views
            myView.onClick {
                val adapterPosition = getBindingAdapterPosition()
                if(adapterPosition >= 0) {
                    itemClicks.invoke(myObject, adapterPosition)
                }
            }
        }

        fun bind(myObject: MyObject) {
            this.myObject = myObject
            // bind data to views
        }
    }
}

你不需要做的事情:

1)你不需要手动拦截触摸事件

2.)您不需要在子附加状态更改侦听器上添乱

3)你不需要RxJava中的PublishSubject/PublishRelay

只需使用点击侦听器。

我发现了使用androidx生命周期可变实时数据的最短方法之一

适配器:

private val onItemClickListener = MutableLiveData<YourAdapterItem>()


override fun onBindViewHolder(holder: GifsViewHolder, position: Int) {
    holder.itemView.setOnClickListener { onItemClickListener.value = gifs[position] }
}
fun getOnItemClickListener(): MutableLiveData<Gif> {
    return onItemClickListener
}

MainActivity的任何地方

    yourFancyAdapter.getOnItemClickListener().observe(this, Observer {
        println(it)
    })