java - Fragment 中的 RecyclerView

Question

我正在遵循 Android 文档示例 here 在 Fragment 内设置 RecyclerView 。

我把我的代码粘贴在下面，没有太多。 (唯一的区别是我使用的是 Fragment 而不是 Activity)。

我收到的错误是:

java.lang.IllegalStateException:指定的子级已经有父级。您必须首先在子级的父级上调用removeView()。

网上解决这个问题的所有方法都是在 fragment 的布局膨胀中添加 false 参数。但我已经这样做了，但仍然收到错误。

我的代码:

主要 Activity

...
mFragmentManager = getSupportFragmentManager();
mFragmentTransaction = mFragmentManager.beginTransaction();
mFragmentTransaction.replace(R.id.containerView,new NewsFragment()).commit();
...

新闻 fragment

public class NewsFragment extends Fragment {

    private RecyclerView mRecyclerView;
    private RecyclerView.Adapter mAdapter;
    private RecyclerView.LayoutManager mLayoutManager;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View v =  inflater.inflate(R.layout.news_layout,container, false);

        mRecyclerView = (RecyclerView) v.findViewById(R.id.my_recycler_view);
        mRecyclerView.setHasFixedSize(true);

        mLayoutManager = new LinearLayoutManager(getActivity());
        mRecyclerView.setLayoutManager(mLayoutManager);

        mAdapter = new NewsAdapter(new String[]{"hello","world","qwert","test","greg","peck"});
        mRecyclerView.setAdapter(mAdapter);

        return v;

    }
}

新闻适配器

public class NewsAdapter extends RecyclerView.Adapter<NewsAdapter.ViewHolder> {
    private String[] mDataset;

    public static class ViewHolder extends RecyclerView.ViewHolder {
        public TextView mTextView;

        public ViewHolder(TextView tv) {
            super(tv);
            mTextView = tv;
        }
    }

    public NewsAdapter(String[] myDataset) {
        mDataset = myDataset;
    }

    @Override
    public NewsAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                                   int viewType) {
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.news_item, parent, false);

        TextView tv = (TextView)v.findViewById(R.id.textView2);
        ViewHolder vh = new ViewHolder(tv);
        return vh;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.mTextView.setText(mDataset[position]);
    }

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

任何帮助将不胜感激!

Answer 1

错误在这一行:

TextView tv = (TextView)v.findViewById(R.id.textView2);
ViewHolder vh = new ViewHolder(tv);

将其更改为:

TextView tv = (TextView)v.findViewById(R.id.textView2);
ViewHolder vh = new ViewHolder(v);

TextView 已经有父 View 。这就是您收到此错误的原因。

更新的代码:

public class NewsAdapter extends RecyclerView.Adapter<NewsAdapter.ViewHolder> {
    private String[] mDataset;

    public static class ViewHolder extends RecyclerView.ViewHolder {
        public TextView mTextView;

        public ViewHolder(View view) {
            super(tv);
           mTextView= (TextView)view.findViewById(R.id.textView2);
        }
    }

    public NewsAdapter(String[] myDataset) {
        mDataset = myDataset;
    }

    @Override
    public NewsAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                                   int viewType) {
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.news_item, parent, false);


        ViewHolder vh = new ViewHolder(v);
        return vh;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.mTextView.setText(mDataset[position]);
    }

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