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

我写了一个库来处理android回收视图项目点击事件。你可以在https://github.com/ChathuraHettiarachchi/RecycleClick上找到完整的教程

RecycleClick.addTo(YOUR_RECYCLEVIEW).setOnItemClickListener(new RecycleClick.OnItemClickListener() {
            @Override
            public void onItemClicked(RecyclerView recyclerView, int position, View v) {
                // YOUR CODE
            }
        });

或处理项目长按即可使用

RecycleClick.addTo(YOUR_RECYCLEVIEW).setOnItemLongClickListener(new RecycleClick.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClicked(RecyclerView recyclerView, int position, View v) {
                // YOUR CODE
                return true;
            }
        });

其他回答

在这里,你可以处理多个点击看到下面的代码,这是非常有效的

    public class RVNewsAdapter extends RecyclerView.Adapter<RVNewsAdapter.FeedHolder> {

    private Context context;
    List<News> newsList;
    // Allows to remember the last item shown on screen
    private int lastPosition = -1;

    public RVNewsAdapter(List<News> newsList, Context context) {
        this.newsList = newsList;
        this.context = context;
    }

    public static class FeedHolder extends RecyclerView.ViewHolder implements OnClickListener {

        ImageView img_main;
        TextView tv_title;
        Button bt_facebook, bt_twitter, bt_share, bt_comment;


        public FeedHolder(View itemView) {
            super(itemView);

            img_main = (ImageView) itemView.findViewById(R.id.img_main);
            tv_title = (TextView) itemView.findViewById(R.id.tv_title);
            bt_facebook = (Button) itemView.findViewById(R.id.bt_facebook);
            bt_twitter = (Button) itemView.findViewById(R.id.bt_twitter);
            bt_share = (Button) itemView.findViewById(R.id.bt_share);
            bt_comment = (Button) itemView.findViewById(R.id.bt_comment);

            img_main.setOnClickListener(this);
            bt_facebook.setOnClickListener(this);
            bt_twitter.setOnClickListener(this);
            bt_comment.setOnClickListener(this);
            bt_share.setOnClickListener(this);

        }


        @Override
        public void onClick(View v) {

            if (v.getId() == bt_comment.getId()) {

                Toast.makeText(v.getContext(), "Comment  " , Toast.LENGTH_SHORT).show();

            } else if (v.getId() == bt_facebook.getId()) {

                Toast.makeText(v.getContext(), "Facebook  " , Toast.LENGTH_SHORT).show();

            } else if (v.getId() == bt_twitter.getId()) {

                Toast.makeText(v.getContext(), "Twitter  " , Toast.LENGTH_SHORT).show();

            } else if (v.getId() == bt_share.getId()) {

                Toast.makeText(v.getContext(), "share  " , Toast.LENGTH_SHORT).show();

            }
            else {
                Toast.makeText(v.getContext(), "ROW PRESSED = " + String.valueOf(getAdapterPosition()), Toast.LENGTH_SHORT).show();
            }
        }
    }

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

    @Override
    public FeedHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.feed_row, parent, false);
        FeedHolder feedHolder = new FeedHolder(view);

        return feedHolder;
    }

    @Override
    public void onBindViewHolder(FeedHolder holder, int position) {

        holder.tv_title.setText(newsList.get(position).getTitle());


        // Here you apply the animation when the view is bound
        setAnimation(holder.img_main, position);
    }

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


    /**
     * Here is the key method to apply the animation
     */
    private void setAnimation(View viewToAnimate, int position) {
        // If the bound view wasn't previously displayed on screen, it's animated
        if (position > lastPosition) {
            Animation animation = AnimationUtils.loadAnimation(context, android.R.anim.slide_in_left);
            viewToAnimate.startAnimation(animation);
            lastPosition = position;
        }
    }


}

伙计们,在你们的主要活动中使用这个代码。非常有效的方法

RecyclerView recyclerView = (RecyclerView) findViewById(R.id.users_list);            
UsersAdapter adapter = new UsersAdapter(users, this);
recyclerView.setAdapter(adapter);
adapter.setOnCardClickListner(this);

下面是适配器类。

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;
        }
    }

在此之后,您将在您的活动中获得这个覆盖方法。

@Override
    public void OnCardClicked(View view, int position) {
        Log.d("OnClick", "Card Position" + position);
    }

最简单的方法如下:

在Adapter类开始时声明全局变量:

// Store out here so we can resuse
private View yourItemView;

然后在onBindViewHolder方法中设置OnClickListener:

@Override
public void onBindViewHolder(BusinessAdapter.ViewHolder holder, int position) {

    // Set up the on click listener
    yourItemView.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            Toast.makeText(mContext,Integer.toString(position),Toast.LENGTH_SHORT).show();
        }
    });

}

其他答案都不正确。

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);
        }
    }
}

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。