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

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);
            }
        });
    }

其他回答

感谢@marmor,我更新了我的答案。

我认为在ViewHolder类构造函数中处理onClick()并通过OnItemClickListener接口将其传递给父类是一个很好的解决方案。

MyAdapter.java

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());
    }
}
}

适配器在其他类中的使用:

MyFragment.java

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
    }
}

}

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); } }

看看我的方法:

首先像这样声明一个接口:

/**
 * Interface used for delegating item click events in a {@link android.support.v7.widget.RecyclerView}
 * Created by Alex on 11/28/2015.
 */
  public interface OnRecyclerItemClickListener<T> {

     /**
      * Called when a click occurred inside a recyclerView item view
      * @param view that was clicked
      * @param position of the clicked view
      * @param item the concrete data that is displayed through the clicked view
      */
      void onItemClick(View view, int position, T item);
   }

然后创建适配器:

public class CustomRecyclerAdapter extends RecyclerView.Adapter {      

    private class InternalClickListener implements View.OnClickListener{

      @Override
      public void onClick(View v) {
        if(mRecyclerView != null && mItemClickListener != null){
            // find the position of the item that was clicked
            int position = mRecyclerView.getChildAdapterPosition(v);
            Data data = getItem(position);
            // notify the main listener
            mItemClickListener.onItemClick(v, position, data);
        }
    }
}

private final OnRecyclerItemClickListener mItemClickListener;
private RecyclerView mRecyclerView;    
private InternalClickListener mInternalClickListener;


/**
 *
 * @param itemClickListener used to trigger an item click event
 */
public PlayerListRecyclerAdapter(OnRecyclerItemClickListener itemClickListener){        
    mItemClickListener = itemClickListener;
    mInternalClickListener = new InternalClickListener();
}

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

    v.setOnClickListener(mInternalClickListener);

    ViewHolder viewHolder = new ViewHolder(v);
    return viewHolder;
}

@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
    // do your binding here
}

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

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

    mRecyclerView = recyclerView;
}

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

    mRecyclerView = null;
}

public Data getItem(int position){
    return mDataset.get(position);
}
}

现在让我们看看如何从一个片段中整合这个:

public class TestFragment extends Fragment implements OnRecyclerItemClickListener<Data>{
   private RecyclerView mRecyclerView;

   @Override
   public void onItemClick(View view, int position, Data item) {
     // do something
   }

   @Override
   public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
      return inflater.inflate(R.layout.test_fragment, container, false);
   }

   @Override
   public void onViewCreated(View view, Bundle savedInstanceState) {
      mRecyclerView = view.findViewById(idOfTheRecycler);
      mRecyclerView .setAdapter(new CustomRecyclerAdapter(this));
   }

检查这一个,我已经实现了所有的事情与适当的方式

RecyclerViewHolder类

public class RecyclerViewHolder extends RecyclerView.ViewHolder  {

    //view holder is for girdview as we used in the listView
    public ImageView imageView,imageView2;
    public RecyclerViewHolder(View itemView) {
        super(itemView);
        this.imageView=(ImageView)itemView.findViewById(R.id.image);
    }

}

适配器

public class RecyclerView_Adapter extends RecyclerView.Adapter<RecyclerViewHolder> {

    //RecyclerView will extend to recayclerview Adapter
    private ArrayList<ModelClass> arrayList;
    private Context context;
    private static RecyclerViewClickListener itemListener;
    //constructor of the RecyclerView Adapter
    RecyclerView_Adapter(Context context,ArrayList<ModelClass> arrayList,RecyclerViewClickListener itemListener){
        this.context=context;
        this.arrayList=arrayList;
        this.itemListener=itemListener;
    }

    @Override
    public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        //this method will inflate the custom layout and return as viewHolder
        LayoutInflater layoutInflater=LayoutInflater.from(parent.getContext());
        ViewGroup mainGroup=(ViewGroup) layoutInflater.inflate(R.layout.single_item,parent,false);
        RecyclerViewHolder listHolder=new RecyclerViewHolder(mainGroup);

        return listHolder;
    }

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

        final ModelClass modelClass=arrayList.get(position);
        //holder
        RecyclerViewHolder mainHolder=(RecyclerViewHolder)holder;
        //convert the drawable image into bitmap
        Bitmap image= BitmapFactory.decodeResource(context.getResources(),modelClass.getImage());
        //set the image into imageView
        mainHolder.imageView.setImageBitmap(image);
        //to handle on click event when clicked on the recyclerview item and
        // get it through the RecyclerViewHolder class we have defined the views there
        mainHolder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //get the position of the image which is clicked
             itemListener.recyclerViewListClicked(v,position);
            }
        });

    }

    @Override
    public int getItemCount() {
        return (null!=arrayList?arrayList.size():0);
    }
}

的接口

public interface RecyclerViewClickListener {

    //this is method to handle the event when clicked on the image in Recyclerview
    public void recyclerViewListClicked(View v,int position);
}

//and to call this method in activity
RecyclerView_Adapter adapter=new RecyclerView_Adapter(Wallpaper.this,arrayList,this);
        recyclerView.setAdapter(adapter);
        adapter.notifyDataSetChanged();


    @Override
    public void  recyclerViewListClicked(View v,int position){

        imageView.setImageResource(wallpaperImages[position]);

    }

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)
    })