让我们看看如何在Jetpack / AndroidX中实现这一点

你需要像这样在viewmodel类中创建一个观察对象

private MutableLiveData<Integer> adapterItem = new MutableLiveData<>();

public MutableLiveData<Integer> getAdapterItem() {
    return adapterItem;
}

public void setAdapterItem(int adapterItem) {
    this.getAdapterItem().setValue(adapterItem);
}

然后在适配器类中，确保将viewmodel引用作为构造函数的参数传递，然后在vieholder上实现clicklistener

    public MyViewHolder(@NonNull View itemView) {
        super(itemView);
        if(itemView != null){
            itemView.setOnClickListener(v -> {
                int adapterPosition = getAdapterPosition();
                viewModel.setAdapterItem(adapterPosition);
            });

        };
    }

然后从活动课上观察变化

    viewModel.getAdapterItem().observe(this, position -> {
        Log.w(TAG, "clicked: " + ridesArray.get(position));
    });

由于API已经发生了根本性的变化，如果你要为每个项目创建一个OnClickListener，这不会让我感到惊讶。不过也没那么麻烦。在你的RecyclerView的实现中。适配器<MyViewHolder>，你应该有:

private final OnClickListener mOnClickListener = new MyOnClickListener();

@Override
public MyViewHolder onCreateViewHolder(final ViewGroup parent, final int viewType) {
    View view = LayoutInflater.from(mContext).inflate(R.layout.myview, parent, false);
    view.setOnClickListener(mOnClickListener);
    return new MyViewHolder(view);
}

onClick方法:

@Override
public void onClick(final View view) {
    int itemPosition = mRecyclerView.getChildLayoutPosition(view);
    String item = mList.get(itemPosition);
    Toast.makeText(mContext, item, Toast.LENGTH_LONG).show();
}

From most of the answers above, they seem to be setting their onclicklisteners to individual items. However, the solution am about to offer is very simple but yet not intuitive to many. Many are forgetting that the other components are always in a parent component which is used to display items in the List or Recycler views. This solution is just about setting a single onclick listener to this parent view and the turn is played. The solution also includes a way to pass the position of the item being clicked on from the list or recycler view. Here, our main rootview is a CardView from the android support library. Here is sample code

public class ListAdapter extends RecyclerView.Adapter<ListAdapter.ViewHolder> {

public static final String LOG_TAG = ListAdapter.class.getSimpleName();
private Cursor mDataset;
private Context mContext;
private ViewHolder mViewHolder;

// Provide a suitable constructor (depends on the kind of dataset)
public ListAdapter(Context context, Cursor Dataset) {
    mDataset = Dataset;
    mContext = context;
}

// Create new views (invoked by the layout manager)
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

    // create a new view
    View v = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.list_business_view, parent, false);

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

public void setData(Cursor newdata) {
    this.mDataset = newdata;
}

// Replace the contents of a view (invoked by the layout manager)
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
//Bind data to other items here. To save time, i have ommited that.
           //here is where we attach a click listerner for an item in the recycler list rather than for each element of a given item.
            holder.card.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(mContext, " Just cliked item at position " + itemPosition, Toast.LENGTH_LONG).show();

            }
        });

    }
}

// Return the size of your dataset (invoked by the layout manager)
@Override
public int getItemCount() {
    if (null != mDataset) {
        return mDataset.getCount();
    }
    return 0;

}


// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public static class ViewHolder extends RecyclerView.ViewHolder{
    // each data item is just a string in this case
    public final TextView mBusinesssName; // View for the business name
    public final TextView mBusinessCategory; //View for the category name
    public final ImageView businessImage; // View for the business category image Image
    public final TextView mBusinessDistance; // View for the distance
    public final CardView card;

    public ViewHolder(View view) {
        super(view);
        mBusinesssName = (TextView) view.findViewById(R.id.list_item_name_textview);
        mBusinessCategory = (TextView) view.findViewById(R.id.list_item_category_textview);
        mBusinessDistance = (TextView) view.findViewById(R.id.list_item_dist_textview);
        businessImage = (ImageView) view.findViewById(R.id.list_item_icon);
        card = (CardView) view.findViewById(R.id.card_view);

    }
}
}

不幸的是，RecyclerView缺少ListView内置的几个功能。 例如，添加OnItemClickListener的能力，当一个项目被单击时触发。 RecyclerView允许你在适配器中设置一个OnClickListener，但是传递那个点击 从你的调用代码，到适配器，再到ViewHolder，监听器是复杂的 要捕捉一个简单的项目单击。

public class ItemClickSupport {
private final RecyclerView mRecyclerView;
private OnItemClickListener mOnItemClickListener;
private OnItemLongClickListener mOnItemLongClickListener;
private View.OnClickListener mOnClickListener = new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (mOnItemClickListener != null) {
            RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
            mOnItemClickListener.onItemClicked(mRecyclerView, holder.getAdapterPosition(), v);
        }
    }
};
private View.OnLongClickListener mOnLongClickListener = new View.OnLongClickListener() {
    @Override
    public boolean onLongClick(View v) {
        if (mOnItemLongClickListener != null) {
            RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
            return mOnItemLongClickListener.onItemLongClicked(mRecyclerView, holder.getAdapterPosition(), v);
        }
        return false;
    }
};
private RecyclerView.OnChildAttachStateChangeListener mAttachListener
        = new RecyclerView.OnChildAttachStateChangeListener() {
    @Override
    public void onChildViewAttachedToWindow(View view) {
        if (mOnItemClickListener != null) {
            view.setOnClickListener(mOnClickListener);
        }
        if (mOnItemLongClickListener != null) {
            view.setOnLongClickListener(mOnLongClickListener);
        }
    }

    @Override
    public void onChildViewDetachedFromWindow(View view) {

    }
};

private ItemClickSupport(RecyclerView recyclerView) {
    mRecyclerView = recyclerView;
    mRecyclerView.setTag(R.id.item_click_support, this);
    mRecyclerView.addOnChildAttachStateChangeListener(mAttachListener);
}

public static ItemClickSupport addTo(RecyclerView view) {
    ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
    if (support == null) {
        support = new ItemClickSupport(view);
    }
    return support;
}

public static ItemClickSupport removeFrom(RecyclerView view) {
    ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
    if (support != null) {
        support.detach(view);
    }
    return support;
}

public ItemClickSupport setOnItemClickListener(OnItemClickListener listener) {
    mOnItemClickListener = listener;
    return this;
}

public ItemClickSupport setOnItemLongClickListener(OnItemLongClickListener listener) {
    mOnItemLongClickListener = listener;
    return this;
}

private void detach(RecyclerView view) {
    view.removeOnChildAttachStateChangeListener(mAttachListener);
    view.setTag(R.id.item_click_support, null);
}

public interface OnItemClickListener {

    void onItemClicked(RecyclerView recyclerView, int position, View v);
}

public interface OnItemLongClickListener {

    boolean onItemLongClicked(RecyclerView recyclerView, int position, View v);
}
}

您还需要定义R.id。使用ids.xml:

 <?xml version="1.0" encoding="utf-8"?>
 <resources>
  <item name="item_click_support" type="id" />
 </resources>

结果代码点击侦听器现在看起来像这样:

ItemClickSupport.addTo(mRecyclerView).setOnItemClickListener(new ItemClickSupport.OnItemClickListener() {
@Override
public void onItemClicked(RecyclerView recyclerView, int position, View v) {
    // do it
}
});

关于recyclerview点击的简要说明，请看看这个littlerobots_blog

这个作品。

public class ServiceListAdapter extends RecyclerView.Adapter<ServiceListAdapter.ViewHolder> {

private final Context mContext;
private List<ServiceListModel> categoryList;
private View.OnClickListener onClickListener;

public ServiceListAdapter(Context mContext, List<ServiceListModel> categoryList, View.OnClickListener onClickListener) {
    this.categoryList = categoryList;
    this.mContext = mContext;
    this.onClickListener = onClickListener;
}

@Override
public ViewHolder onCreateViewHolder(final ViewGroup parent, final int viewType) {
    final LayoutInflater inflater = LayoutInflater.from(parent.getContext());
    final RowServiceListBinding binding = DataBindingUtil.inflate(inflater, R.layout.row_service_list, parent, false);
    return new ViewHolder(binding.getRoot(), binding);
}

@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
    holder.binding.rlService.setOnClickListener(onClickListener);
    holder.binding.rlService.setTag(position);
}

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

public class ViewHolder extends RecyclerView.ViewHolder {
    private final RowServiceListBinding binding;

    public ViewHolder(final View view, final RowServiceListBinding binding) {
        super(view);
        this.binding = binding;
    }

    @UiThread
    public void bind(final ServiceListModel mAddressModel) {
        //this.binding.setAddress(mAddressModel);
    }
}
}

在活动/片段中使用

ServiceListAdapter adapter = new ServiceListAdapter(context, serviceList, new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            switch (v.getId()) {
                case R.id.rlService:
                    int pos = (int) v.getTag();
                    serviceList.remove(position);
                    break;
            }
        }
    });

对于kotlin句柄，根据Jacobs的回答单击RecyclerView答案

创建类RecyclerItemClickListener:

class RecyclerItemClickListener(context: Context, recyclerView: RecyclerView, listner: OnItemClickListener) : RecyclerView.OnItemTouchListener {

    var mGestureDetector: GestureDetector
    var mListner: OnItemClickListener
    
    interface OnItemClickListener {
        fun onItemClick(view: View, position: Int)
        fun onLongItemClick(view: View, position: Int)
    }

    init {
        this.mListner = listner
        mGestureDetector = GestureDetector(context, object : GestureDetector.SimpleOnGestureListener() {
            override fun onSingleTapUp(e: MotionEvent?): Boolean = true
            
            override fun onLongPress(e: MotionEvent?) {
                val child: View? = recyclerView.findChildViewUnder(e!!.getX(), e.getY())
                if (child != null && mListner != null) {
                    mListner.onLongItemClick(child, recyclerView.getChildAdapterPosition(child))
                }
            }
        })
    }

    override fun onTouchEvent(rv: RecyclerView, e: MotionEvent) = Unit

    override fun onInterceptTouchEvent(view: RecyclerView, e: MotionEvent): Boolean {
        val childView: View? = view.findChildViewUnder(e!!.getX(), e.getY())
        if (childView != null && mListner != null && mGestureDetector.onTouchEvent(e)) {
            mListner.onItemClick(childView, view.getChildAdapterPosition(childView))
            return true
        }
        return false
    }

    override fun onRequestDisallowInterceptTouchEvent(disallowIntercept: Boolean) = Unit

}

点击Any RecyclerView(在活动/片段内):

recyclerView.addOnItemTouchListener(
    RecyclerItemClickListener(this, recyclerView, object : RecyclerItemClickListener.OnItemClickListener {
        override fun onItemClick(view: View, position: Int) {
            // TODO catch click
        }

        override fun onLongItemClick(view: View, position: Int) {
            // TODO catch click
        }
    })
)