片段中的RecyclerView

Question

I am setting up a RecyclerView inside a Fragment following the Android docs example here .

I pasted my code below, there is not much. (The only difference is I'm using a Fragment instead of an Activity).

The error I'm getting is:

java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.

All solutions to this problem online are to add false argument in layout inflation for fragment. But I've already done this, and I still get the error.

My code:

MainActivity

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

NewsFragment

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;

    }
}

NewsAdapter

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;
    }
}

Any help would be hugely appreciated!

Answer 1

The error is on this line:

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

Change it to:

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

The text view is already having a parent. That's why you are getting this error.

Updated code:

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;
    }
}