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

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。

其他回答

使用PlaceHolderView

@Layout(R.layout.item_view_1)
public class View1{

    @View(R.id.txt)
    public TextView txt;

    @Resolve
    public void onResolved() {
        txt.setText(String.valueOf(System.currentTimeMillis() / 1000));
    }

    @Click(R.id.btn)
    public void onClick(){
        txt.setText(String.valueOf(System.currentTimeMillis() / 1000));
    }
}

修改了我的评论…

public class MyViewHolder extends RecyclerView.ViewHolder {

        private Context mContext;

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

            mContext = itemView.getContext();

            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {

                    int itemPosition = getLayoutPosition();
                    Toast.makeText(mContext, "" + itemPosition, Toast.LENGTH_SHORT).show();

                }
            });
        }

访问rowLayout(cell)的mainView为你的RecyclerView和在你的OnBindViewHolder写以下代码:

    @Override
    public void onBindViewHolder(MyViewHolder holder, final int position) {
        Movie movie = moviesList.get(position);
        holder.mainView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                System.out.println("pos " + position);
            }
        });
    }

RecyclerView是如何不同于Listview?

一个区别是有一个LayoutManager类和RecyclerView,通过它你可以像-一样管理你的RecyclerView

水平或垂直滚动线性layoutmanager GridLayout by GridLayoutManager 交错网格布局由StaggeredGridLayoutManager

就像水平滚动的RecyclerView-

LinearLayoutManager llm = new LinearLayoutManager(context);
llm.setOrientation(LinearLayoutManager.HORIZONTAL);
recyclerView.setLayoutManager(llm);

这对我很管用。希望能有所帮助。最简单的方法。

内部视图Holder

class GeneralViewHolder extends RecyclerView.ViewHolder {
    View cachedView = null;

    public GeneralViewHolder(View itemView) {
        super(itemView);
        cachedView = itemView;
    }

内部OnBindViewHolder ()

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
            final GeneralViewHolder generalViewHolder = (GeneralViewHolder) holder;
            generalViewHolder.cachedView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(context, "item Clicked at "+position, Toast.LENGTH_SHORT).show();
                }
            });

如果你对这个解决方案有任何问题,请告诉我?