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));
    });

这里有一个策略，它给出了一个类似于ListView实现的结果，因为你可以在活动或片段级别而不是适配器或ViewHolder级别定义侦听器。它还定义了一些抽象类，这些抽象类负责适配器和持有者的大量样板工作。

抽象类

首先，定义一个抽象Holder，它扩展了RecyclerView。并定义了一个泛型数据类型T，用于将数据绑定到视图。bindViews方法将由一个子类实现，用于将数据映射到视图。

public abstract class Holder<T> extends RecyclerView.ViewHolder {
    T data;

    public Holder(View itemView) {
        super(itemView);
    }

    public void bindData(T data){
        this.data = data;
        bindViews(data);
    }

    abstract protected void bindViews(T data);
}

同样，创建一个抽象适配器，扩展RecyclerView.Adapter<Holder<T>>。这定义了3个接口方法中的2个，子类将需要实现最后一个onViewHolderCreated方法。

public abstract class Adapter<T> extends RecyclerView.Adapter<Holder<T>> {
    List<T> list = new ArrayList<>();

    @Override
    public void onBindViewHolder(Holder<T> holder, int position) {
        holder.bindData(list.get(position));
    }

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

    public T getItem(int adapterPosition){
        return list.get(adapterPosition);
    }
}

具体类

现在创建一个扩展Holder的新具体类。该方法只需定义视图并处理绑定。这里我使用ButterKnife库，但请随意使用itemView.findViewById(…)方法代替。

public class PersonHolder extends Holder<Person>{
    @Bind(R.id.firstname) TextView firstname;
    @Bind(R.id.lastname) TextView lastname;

    public PersonHolder(View view){
        super(view);
        ButterKnife.bind(this, view);
    }

    @Override
    protected void bindViews(Person person) {
        firstname.setText(person.firstname);
        lastname.setText(person.lastname);
    }
}

最后，在持有RecyclerView的Activity或Fragment类中，你会有这样的代码:

// Create adapter, this happens in parent Activity or Fragment of RecyclerView
adapter = new Adapter<Person>(){
    @Override
    public PersonHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.layout_person_view, parent, false);

        PersonHolder holder = new PersonHolder(v);
        v.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View v) {
                int itemPos = holder.getAdapterPosition();
                Person person = getItem(itemPos);

                // do something with person
                EventBus.getDefault().postSticky(new PersonClickedEvent(itemPos, person));
            }
        });

        return holder;
    }
};

对我来说，这是最好的方法:

class YourRecyclerAdapter extends RecyclerView.Adapter<ContactViewHolder> implements View.OnClickListener { 
  ...
  @Override
  public void onClick(View view) {
        int itemPosition = vRecycle.getChildPosition(view);
        //And use itemPosition to get the item from your collection. This way you dont restrain the ViewHolder with a OnClick callback
    }
  ...
}

nhaarman答案的Kotlin实现:

mRecyclerView.addOnItemTouchListener(object  : RecyclerItemClickListener(this, mRecyclerView,object :RecyclerItemClickListener.OnItemClickListener{
            override fun onItemClick(view: View, position: Int) {

            }

            override fun onLongItemClick(view: View?, position: Int) {

            }
}){})

RecyclerItemClickListener.java:

import android.content.Context
import android.support.v7.widget.RecyclerView
import android.view.GestureDetector
import android.view.MotionEvent
import android.view.View


open class RecyclerItemClickListener(context: Context, recyclerView: RecyclerView, private val mListener: OnItemClickListener?) : RecyclerView.OnItemTouchListener {

    private var mGestureDetector: GestureDetector

    interface OnItemClickListener {
        fun onItemClick(view: View, position: Int)

        fun onLongItemClick(view: View?, position: Int)
    }

    init {
        mGestureDetector = GestureDetector(context, object : GestureDetector.SimpleOnGestureListener() {
            override fun onSingleTapUp(e: MotionEvent): Boolean {
                return true
            }

            override fun onLongPress(e: MotionEvent) {
                val child = recyclerView.findChildViewUnder(e.x, e.y)
                if (child != null && mListener != null) {
                    mListener.onLongItemClick(child, recyclerView.getChildAdapterPosition(child))
                }
            }
        })
    }

    override fun onInterceptTouchEvent(view: RecyclerView, e: MotionEvent): Boolean {
        val childView = view.findChildViewUnder(e.x, e.y)
        if (childView != null && mListener != null && mGestureDetector.onTouchEvent(e)) {
            mListener.onItemClick(childView, view.getChildAdapterPosition(childView))
            return true
        }
        return false
    }

    override fun onTouchEvent(view: RecyclerView, motionEvent: MotionEvent) {}

    override fun onRequestDisallowInterceptTouchEvent(disallowIntercept: Boolean) {}
}

根据Yigit Boyar的说法，在RecyclerView上注册点击的最好方法是在ViewHolder的创建中定义点击，而不是仅仅为onBindViewHolder绑定的每个项目创建一个新的onClickListener

例子:

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseViewHolder<*> {
   val itemBinding = LayoutInflater.from(context).inflate(R.layout.my_layout, parent, false)

   val vh = MainViewHolder (itemBinding)
   vh.itemView.setOnClickListener {
       val pos = vh.adapterPosition
       if(pos != NO_POSITION){
           itemClickLister.onCocktailClick(myList[pos],pos)
       }
   }

   return vh
}

这就是我最后需要的东西，以防有人发现它有用:

public static class ViewHolder extends RecyclerView.ViewHolder {

    public ViewHolder(View item) {

        super(item);
        item.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.d("RecyclerView", "onClick：" + getAdapterPosition());
            }
        });

    }
}

来源:http://blog.csdn.net/jwzhangjie/article/details/36868515