```
public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    RecyclerView list = (RecyclerView) findViewById(R.id.list);
    list.setLayoutManager(new LinearLayoutManager(this));
    final RecyclerView.Adapter adapter = getAdapter();
    list.setAdapter(adapter);

    adapter.notifyItemChanged(1, new Object());//this doesn't work
    list.post(new Runnable() {
        @Override
        public void run() {
            adapter.notifyItemChanged(1, new Object());//this works
        }
    });

}

@NonNull
private RecyclerView.Adapter getAdapter() {
    return new RecyclerView.Adapter() {
        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            return new ItemViewHolder( LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.list_view_item, parent, false));
        }

        @Override
        public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
            ItemViewHolder item = (ItemViewHolder) holder;
            item.tv.setText("test");
        }

        @Override
        public void onBindViewHolder(RecyclerView.ViewHolder holder, int position, List payloads) {
            if(payloads.isEmpty())
                onBindViewHolder(holder, position);
            else{
                ItemViewHolder item = (ItemViewHolder) holder;
                item.tv.setText("changed!!!!!! ");
            }
        }

        @Override
        public int getItemCount() {
            return 40;
        }

        class ItemViewHolder extends RecyclerView.ViewHolder{
            TextView tv;
            ItemViewHolder(View itemView) {
                super(itemView);
                tv = (TextView) itemView.findViewById(R.id.tv);
            }
        }
    };
}}

```

very simple example here just to test `notifyItemChanged`, it works only when post to the Message queue, but not by invoking directly after `setAdapter`.
`setAdapter` triggers a call to `requestlayout()`, does that mean `notifyItemChanged` can't happen if it is in middle of laying out items?