android - Android recyclerView findViewHolderForAdapterPosition返回null

我想以编程方式单击recyclerView中的一个项目，发现a way可以这样做:

recyclerView.findViewHolderForAdapterPosition(0).itemView.performClick();

但它对我不起作用，findViewHolderForAdapterPosition只会返回null。

我是否错过了代码中的某些内容？

HistoryListAdapter:

public class HistoryListAdapter extends RecyclerView.Adapter<HistoryListAdapter.ViewHolder> {
private static ArrayList<RecordItem> recordItems;
private static FragmentActivity activity;
private static RecordList recordList;

public HistoryListAdapter(ArrayList<RecordItem> recordItems, FragmentActivity FA, RecordList FRL) {
    this.recordItems = recordItems;
    this.activity = FA;
    this.recordList = FRL;
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    // create a new view
    View itemLayoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.recorditem, parent, false);
    return new ViewHolder(itemLayoutView);
}

@Override
public void onBindViewHolder(final ViewHolder viewHolder, final int position) {
    // TextView setText ...
}

// Return the size of the itemsData (invoked by the layout manager)
@Override
public int getItemCount() {
    return recordItems.size();
}

// inner class to hold a reference to each item of RecyclerView
public static class ViewHolder extends RecyclerView.ViewHolder{
    public TextView result, datetime;

    public ViewHolder(View itemLayoutView) {
        super(itemLayoutView);
        itemLayoutView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (activity != null) {
                    // do something...
                }
            }
        });
        result = (TextView) itemLayoutView.findViewById(R.id.result);
        heartrate = (TextView) itemLayoutView.findViewById(R.id.heartrate);
        datetime = (TextView) itemLayoutView.findViewById(R.id.datetime);
    }
}
}

记录列表:

RecyclerView listView = (RecyclerView) layoutView.findViewById(R.id.listView);
HistoryListAdapter listadapter = new HistoryListAdapter(itemsToShow, getActivity(), RecordList.this);
listView.swapAdapter(listadapter, false);
listView.findViewHolderForAdapterPosition(0).itemView.performClick();

我省略了一些代码，但这不应影响代码的整体结构。

最佳答案

根据official documentation:



使用findViewHolderForAdapterPosition()是不安全的。

在listView.swapAdapter(listadapter, false);之后调用此方法时，由于会调用null，因此总会得到一个notifyDataSetChanged()。

关于android - Android recyclerView findViewHolderForAdapterPosition返回null，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/32836844/