Question

我从游标中删除了可能性，该函数正常工作，但是CursorAdapter不会在notifyDataSetChanged（）上更新，任何人都有任何想法???目前看到更改的唯一方法是退出应用并再次运行

public class DiaryFragment extends Fragment implements LoaderManager.LoaderCallbacks<Cursor>, AdapterView.OnItemClickListener {
    private GridView mGridView;
    private View mEmptyViews;
    private TextView mAddNewDiaryEntry;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_diary, container, false);
        setHasOptionsMenu(true);
        getLoaderManager().initLoader(0, null, this);
        mGridView = (GridView) view.findViewById(R.id.gridview);
        mGridView.setAdapter(new DiaryAdapter(getActivity()));
        mGridView.setOnItemClickListener(this);
        return view;
    }
    @Override
    public void onResume() {
        super.onResume();
        GALogEvent.logScreen(getActivity(), "Diary");
        getLoaderManager().restartLoader(0, null, this);
    }
    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        super.onCreateOptionsMenu(menu, inflater);

        getActivity().getMenuInflater().inflate(R.menu.diary, menu);
    }
    private CursorAdapter getAdapter() {
        return ((CursorAdapter) mGridView.getAdapter());
    }
    public static Fragment newInstance() {
        return new DiaryFragment();
    }
    @Override
    public Loader<Cursor> onCreateLoader(int id, Bundle args) {
        return new CursorLoader(getActivity(),ContentProvider. URI, null, null, null, ContentProvider.DIARY_DATE + " DESC");
    }
    @Override
    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
        getAdapter().swapCursor(data);
        if (data != null && data.getCount() > 0) {
            mGridView.setVisibility(View.VISIBLE);
            mEmptyViews.setVisibility(View.GONE);
        }
    }
    @Override
    public void onLoaderReset(Loader<Cursor> loader) {
        getAdapter().swapCursor(null);
    }
    @Override
    public void onItemClick(AdapterView<?> parent, View view, final int position, long id) {
        Cursor c = (Cursor) parent.getAdapter().getItem(position);
        int diaryEntryId = c.getInt(c.getColumnIndex(ContentProvider.ID));
        Intent intent = new Intent(getActivity(), AddDiaryEntryActivity.class);
        boolean didSmoke = c.getInt(c.getColumnIndex(ContentProvider.DIARY_DID_SMOKE)) != 0;
        intent.putExtra(Constants.DIARY_UPDATE_STATUS, didSmoke);
        intent.putExtra(Constants.DIARY_ENTRY, diaryEntryId);
        startActivity(intent);
    }
    private class DiaryAdapter extends CursorAdapter {
        private final LayoutInflater mLayoutInflater;
        public DiaryAdapter(Context context) {
            super(context, null, true);
            mLayoutInflater = LayoutInflater.from(context);
        }
        @Override
        public View newView(Context context, Cursor cursor, ViewGroup parent) {
            return mLayoutInflater.inflate(R.layout.row_diary, parent, false);
        }
        @Override
        public void bindView(View view, Context context, final Cursor cursor) {
            final int idCraving = cursor.getInt(cursor.getColumnIndex(ContentProvider.ID));
          final ImageView deleteDiaryEntry;
            deleteDiaryEntry = (ImageView) view.findViewById(R.id.remove_registry_from_diary);
            deleteDiaryEntry.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    getActivity().getContentResolver().delete(ContentProvider. URI, " _id = ? ", new String[]{"" + idCraving});
                    getAdapter().notifyDataSetChanged();
                }
            });
        }
    }
}

Answer 1

在ContentProvider的delete（）方法中，您需要使用以下代码行：

getContext().getContentResolver().notifyChange(uri, null);

从官方文档中，此行将通知CursorAdapter对象发生了更改。如果您没有这一行，只有当代码执行数据库的新查找时才会看到更改，当您退出并重新打开应用程序时，该数据库会发生。

CursorAdapter不想更新

1 个答案: