RecyclerView没有OnClickListener，必须自己实现它。

我喜欢在适配器中添加OnItemClickListener接口，当您从ViewHolder中单击项目视图时调用onClick方法。因此，管理项目点击的职责不在ViewHolder和Adapter的范围内。将决定做什么的活动或片段

为监听器和监听器对象添加接口。

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

  ...

  private static OnItemClickListener onItemClickListener;

  ...

  public static interface OnItemClickListener {
      public void onItemClick(View view, int position);
  }

  ...
}

我们捕获项目根视图的单击，以及当回调触发时适配器上的onClick侦听器调用。

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

  ...

  private static OnItemClickListener onItemClickListener;

  ...

  public static interface OnItemClickListener {
      public void onItemClick(View view, int position);
  }

  ...

  public static class ViewHolder extends RecyclerView.ViewHolder {
      public ImageView imageView;

      public ViewHolder(View itemRootView) {
          super(itemRootView);
          imageView = (ImageView) itemRootView.findViewById(R.id.itemImage);

          itemRootView.setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View view) {
                  int position  = ViewHolder.super.getAdapterPosition();
                  onItemClickListener.onItemClick(view,position);
              }
          });
      }
  }
}

由于活动或片段，片段在我们的情况下，我们分配一个监听器到适配器和onClick回调，我们将获得选定的项目的位置和打开一个详细的活动项目。

public class ItemsFragment extends Fragment {
    ...
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
       ...    
        ((ItemsAdapter) adapter).setOnItemClickListener(new ItemsAdapter.OnItemClickListener() {
            @Override
            public void onItemClick(View view, int position) {
                //Do something when an item has been clicked
            }
        });
        ...
    }
...
}

对我来说，最干净的方法就是这个。

适配器的构造函数

private class EnvironmentTypeRecyclerViewAdapter extends RecyclerView.Adapter<EnvironmentTypeRecyclerViewAdapter.ViewHolder>
{
     private final EnvironmentTypeRecyclerViewAdapterListener mEnvironmentTypeRecyclerViewAdapterListener;
     private List<Environment> mEnvironmentsData;

     public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener
     {
         public ViewHolder(View v)
         {
             super(v);
             v.setOnClickListener(this);

         }

         @Override
         public void onClick(View v)
         {
              Environment environment = mEnvironmentsData.get(getAdapterPosition());
              if (mEnvironmentTypeRecyclerViewAdapterListener != null && environment != null) {
                      mEnvironmentTypeRecyclerViewAdapterListener.onListItemSelected(environment);      
              }
        }

        public EnvironmentTypeRecyclerViewAdapter(List<SmallCellEnvironment> environments, EnvironmentTypeRecyclerViewAdapterListener environmentTypeRecyclerViewAdapterListener)
        {
            mEnvironmentTypeRecyclerViewAdapterListener = environmentTypeRecyclerViewAdapterListener;
            mEnvironmentsData = environments;
        }
}

链接接口

private interface EnvironmentTypeRecyclerViewAdapterListener
{
    void onListItemSelected(Environment environment);
}

这对我来说很管用。将OnClickListener附加到onBindView。我真的不知道这是否会影响性能，但它似乎用很少的代码就能很好地工作。

public void onBindViewHolder(ViewHolder holder, final int position) {
    holder.view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(context, "Recycle Click" + position, Toast.LENGTH_SHORT).show();
            }
    });
}

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();
}

如果你想在个别项目上捕捉点击事件，那么只需在ViewHolder类中实现OnClickListener，然后在个别视图或整个itemView上设置点击侦听器。

下面的例子说明了同样的情况

public  class ContactViewHolder extends RecyclerView.ViewHolder implements OnClickListener
    {
        TextView txt_title,txt_name,txt_email;

        public ContactViewHolder(View itemView) 
        {
            super(itemView);
            txt_title = (TextView)itemView.findViewById(R.id.txt_title);
            txt_name  = (TextView)itemView.findViewById(R.id.txt_name);
            txt_email = (TextView)itemView.findViewById(R.id.txt_email);

            txt_name.setOnClickListener(this);
            txt_email.setOnClickListener(this);
            itemView.setOnClickListener(this);
        }

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            if(v == itemView)
            {
                Toast.makeText(RecyclerDemoActivity.this, "Visiting Card Clicked is ==>"+txt_name.getText(), Toast.LENGTH_SHORT).show();
            }

            if(v == txt_name)
            {
                Toast.makeText(RecyclerDemoActivity.this, "Name ==>"+txt_name.getText(), Toast.LENGTH_SHORT).show();
            }

            if(v == txt_email)
            {
                Toast.makeText(RecyclerDemoActivity.this, "Email ==>"+txt_email.getText(), Toast.LENGTH_SHORT).show();
            }
        }

    }
} 

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));
    });