扩展RecyclerView的最后一项不起作用

Question

我有一个RecyclerViewAdapter，它在OnCLick中实现了一个expands方法，但在最后一个项目中展开，不起作用。

public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.DataObjectHolder> {

private static String LOG_TAG = "MyRecylerViewAdapter";
private ArrayList<Person>  mDataset;
private static MyClickListener myClickListener;
private int mExpandedPosition;
private ViewGroup viewGroup;

public static class DataObjectHolder extends RecyclerView.ViewHolder
        implements View
        .OnClickListener {
    TextView label;
    TextView dateTime;
    LinearLayout txtDetails;

    public DataObjectHolder(View itemView) {
        super(itemView);
        label = (TextView) itemView.findViewById(R.id.textView);
        dateTime = (TextView) itemView.findViewById(R.id.textView2);
        txtDetails = (LinearLayout) itemView.findViewById(R.id.txtDetails);
        Log.i(LOG_TAG, "Adding Listener");
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        myClickListener.onItemClick(getAdapterPosition(), v);
    }
}

public void setOnItemClickListener(MyClickListener myClickListener) {
    this.myClickListener = myClickListener;
}

public MyRecyclerViewAdapter(ArrayList<Person> myDataset) {
    mDataset = myDataset;

}

@Override
public DataObjectHolder onCreateViewHolder(ViewGroup parent,
                                           int viewType) {
    View view = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.card_view_row, parent, false);

    viewGroup = parent;

    DataObjectHolder dataObjectHolder = new DataObjectHolder(view);

    //Para expandir
    mExpandedPosition = -1;

    return dataObjectHolder;
}

@Override
public void onBindViewHolder(final DataObjectHolder holder, final int position) {
    holder.label.setText(mDataset.get(position).getCompletName());
    holder.dateTime.setText("" + mDataset.get(position).getAge());


    final boolean isExpanded = position==mExpandedPosition;
    holder.txtDetails.setVisibility(isExpanded?View.VISIBLE:View.GONE);
    holder.itemView.setActivated(isExpanded);
    holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mExpandedPosition = isExpanded ? -1:position;

          //  TransitionManager.beginDelayedTransition(viewGroup, new Fade());
            notifyDataSetChanged();
        }
    });

}

public void addItem(Person dataObj, int index) {
    mDataset.add(index, dataObj);
    notifyItemInserted(index);
}

public void deleteItem(int index) {
    mDataset.remove(index);
    notifyItemRemoved(index);
}

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

}

有人有同样的问题吗？

有任何建议吗？

感谢。

PD：对不起我的英语技能。