Question

我尝试使用recyclerview填充loader，但适配器只会绑定数据库中的前五项，然后对数据库中的每个其他项重复。

为清楚起见，它看起来像这样：

第1项

第2项

第3项

第4项

第5项

第1项

第2项

...

项目数仍然与数据库中的项目数相匹配。我还测试了光标并正确打印了每个项目，所以我假设问题是适配器。这就是我正在使用的：

class LibraryAdapter extends RecyclerView.Adapter<LibraryAdapter.LibraryViewHolder> {

private Context mContext;
private Cursor mCursor;

LibraryAdapter(Context context, Cursor cursor){
    this.mContext = context;
    this.mCursor = cursor;
    setHasStableIds(true);
}

static class LibraryViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

    private TextView titleText;
    private TextView numText;

    LibraryViewHolder(View itemView) {
        super(itemView);
        titleText = (TextView) itemView.findViewById(R.id.titleText);
        numText = (TextView) itemView.findViewById(R.id.numText);
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
         ....
    }
}

@Override
public LibraryAdapter.LibraryViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
    return new LibraryViewHolder(view);
}

@Override
public void onBindViewHolder(LibraryAdapter.LibraryViewHolder holder, int position) {
    LibraryModel item = getData(position);
    holder.titleText.setText(item.getTitle());
    holder.numText.setText(item.getNum() + " items");
}

@Override
public int getItemCount() {
    return (mCursor != null) ? mCursor.getCount() : 0;
}

private Cursor swapCursor(Cursor cursor){
    if(mCursor == cursor){
        return null;
    }
    Cursor oldCursor = mCursor;
    this.mCursor = cursor;
    if(cursor != null){
        this.notifyDataSetChanged();
    }
    return oldCursor;
}

void changeCursor(Cursor cursor){
    Cursor oldCursor = swapCursor(cursor);
    if (oldCursor != null){
        oldCursor.close();
    }
}

private LibraryModel getData(int position){
    mCursor.moveToPosition(position);
    String title = mCursor.getString(mCursor.getColumnIndex(DatabaseContract.LibraryEntry.COLUMN_TITLE));
    int num = mCursor.getInt(mCursor.getColumnIndex(DatabaseContract.LibraryEntry.COLUMN_NUMBER));
    LibraryModel item = new LibraryModel();
    item.setTitle(title);
    item.setNum(num);
    return item;
}
}

在片段上：

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View root = inflater.inflate(R.layout.fragment_alltracks, container, false);
    libraryRecyclerview = (RecyclerView) root.findViewById(R.id.list);
    RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getContext());
    libraryRecyclerview.setLayoutManager(mLayoutManager);
    mAdapter = new LibraryAdapter(getContext(), null, allTracks);
    libraryRecyclerview.setAdapter(mAdapter);
    return root;
}

@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    getLoaderManager().initLoader(1, null, this);
}

@Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
    Uri uri = DatabaseContract.LibraryEntry.CONTENT_URI;
    String[] projection = {
            DatabaseContract.LibraryEntry.TABLE_NAME + "." + DatabaseContract.LibraryEntry._ID,
            DatabaseContract.LibraryEntry.COLUMN_TITLE,
            DatabaseContract.LibraryEntry.COLUMN_NUM
    };
    return new CursorLoader(getContext(), uri, projection, null, null, null);
}

@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
    mAdapter.changeCursor(data);
}

@Override
public void onLoaderReset(Loader<Cursor> loader) {
    mAdapter.changeCursor(null);
}

Answer 1

对于任何仍然绊倒这个问题的人：

我遇到了同样的问题，在回收站视图中重复了 5 个相同的条目。

解决我的问题的只是删除

adapter.setHasStableIds(true)

当然，这让我解决了其他问题，但我设法用这个显示了我的所有条目。

Recyclerview仅显示游标中的前五项

1 个答案: