指定的孩子已经有一个父母，RecyclerView

Posted 2023-04-15

【中文标题】指定的孩子已经有一个父母，RecyclerView

【英文标题】：The specified child already has a parent, RecyclerView

【发布时间】：2017-05-21 04:43:56

【问题描述】：

那是我的适配器：

public class ListAdapter extends RecyclerView.Adapter<ListAdapter .ViewHolder> 
    private List<String> mDataset;

    // Provide a reference to the views for each data item
    // Complex data items may need more than one view per item, and
    // you provide access to all the views for a data item in a view holder
    public static class ViewHolder extends RecyclerView.ViewHolder 
        // each data item is just a string in this case
        public TextView mTextView;
        public ViewHolder(TextView v) 
            super(v);
            mTextView = v;
        
    

    // Provide a suitable constructor (depends on the kind of dataset)
    public ListAdapter (List<String> myDataset) 
        mDataset = myDataset;
    

    // Create new views (invoked by the layout manager)
    @Override
    public ListAdapter .ViewHolder onCreateViewHolder(ViewGroup parent,
                                                   int viewType) 
        // create a new view
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.item_list_out_in, parent, false);

        TextView itemList = (TextView) v.findViewById(R.id.item_list);
        ViewHolder vh = new ViewHolder(itemList);
        return vh;
    

    // Replace the contents of a view (invoked by the layout manager)
    @Override
    public void onBindViewHolder(ViewHolder holder, int position) 
        // - get element from your dataset at this position
        // - replace the contents of the view with that element
        holder.mTextView.setText(mDataset.get(position));
    

    // Return the size of your dataset (invoked by the layout manager)
    @Override
    public int getItemCount() 
        return mDataset.size();
    

那是片段：

public class OutInListFragment extends Fragment 
    private RecyclerView mRecyclerView;
    private LinearLayoutManager mLayoutManager;
    private ListAdapter mAdapter;
    private List<String> list = new ArrayList<String>();

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) 
        // Inflate the layout for this fragment
        View view= inflater.inflate(R.layout.fragment_in_out_list, container, false);
        mRecyclerView = (RecyclerView) view.findViewById(R.id.list_in_out);
        if(mRecyclerView!=null)
            Bundle bundle=getArguments();
            Cursor listCursor = getList(bundle.getInt("day"),bundle.getInt("month"),bundle.getInt("year"));
            // use this setting to improve performance if you know that changes
            // in content do not change the layout size of the RecyclerView
            mRecyclerView.setHasFixedSize(true);

            // use a linear layout manager
            mLayoutManager = new LinearLayoutManager(getContext());
            mRecyclerView.setLayoutManager(mLayoutManager);

            if(listCursor.getCount()>0) 
                listCursor.moveToFirst();
                int i = 0, index;
                while (!listCursor.isAfterLast()) 
                    index = listCursor.getColumnIndex("amount");
                    list.add(listCursor.getString(index));
                    listCursor.moveToNext();
                    i++;
                
                listCursor.close();
            else
               list.add("0");
            
            // specify an adapter (see also next example)
            mAdapter = new ListAdapter(list);
            mRecyclerView.setAdapter(mAdapter);
        else
            Toast.makeText(getContext(),"Error", Toast.LENGTH_SHORT).show();
        
        return view;
    

我收到此错误：

java.lang.IllegalStateException: 指定的孩子已经有一个 父母。您必须先在孩子的父母上调用 removeView()。

【参考方案1】：

只需替换

ViewHolder vh = new ViewHolder(itemList);

与

ViewHolder vh = new ViewHolder(v);

在onCreateViewHolder(ViewGroup parent, int viewType).

因为itemList 是v 的孩子。

【参考方案2】：

您必须使用ViewHolder vh = new ViewHolder(v); 而不是ViewHolder vh = new ViewHolder(itemList);，因为TextView itemList 已经有一个父级。

【讨论】：

感谢您的回答。现在我必须更改 viewHolder 并在其中设置 textview，对吗？

可以，你可以在ViewHolder里面初始化TextView。