Android: Spinner does not update after change of dataset

问题

In my app the spinne shows the active items (I use Loader of support library to load them). The init of spinner works fine and it shows only the active items.

But I got the followeing problem: When I edit the items in another activity and store them (active and deactivat some of them) an go back (Back-Button), then I see the "old" list of items in the spinner. The adapter get the new cursor with correct data, but the spinner does not refresh his list.

What can I do to refresh the spinner list?

In onCreate() I initialize the Spinner

_ItemSpinner = (Spinner) getView().findViewById(R.id.spn_itemss);
_ItemAdapter = new AdvancedCursorAdapter(
    getActivity(),
    R.layout.spinner_2line_item,
    null, _ColumnList, _ColumnViews, 0);
_ItemSpinner.setAdapter(_ItemAdapter);

In onResume() I start the loader initialisation

@Override
public void onResume() {
    getLoaderManager().initLoader(1, null, this);
    super.onStart();
}

In onLoadFinished(Loader<Cursor> loader, Cursor data) I swap the cursor for the adapter

_ItemAdapter.swapCursor(data);

回答1:

you can call the adapter's notifyDataSetChanged method

回答2:

Finally I found out, not why, but which, element destroy the refresh of the spinner.

I used two different URIs of the same ContentProvider for updating all items and showing only active items

CONTENT_URI_ITEMS
CONTENT_URI_ACTIVE_ITEMS

If I use the same URI for updating and showing (with needed active filter), the spinner list will be updated. If I use different URIs, the spinner shows old data.

I don't understand this behavior (the cursor returns correct number of items, but the spinner doesn't care), but I have a work around that works.

Store data:

getActivity().getContentResolver().update(
    RecordsContentProvider.CONTENT_URI_ITEMS,
    _Changes,
    COLUMN_ID + " =?",
    new String[] { String.valueOf(_ID) });

Before (get data) - doesn't work:

CursorLoader curLoader = new CursorLoader(this.getActivity(),
    RecordsContentProvider.CONTENT_URI_ACTIVE_ITEMS,
    _ITEMS_PROJECTION,
    null, null, null);

After (get data) - work:

CursorLoader curLoader = new CursorLoader(this.getActivity(),
    RecordsContentProvider.CONTENT_URI_ITEMS,
    _ITEMS_PROJECTION,
    COLUMN_IS_ACTIVE + " =1", null, null);

notifyDataSetChanged is not necessary, if the underlying ContentProvider do this for you like this: (getContext().getContentResolver().notifyChange(uri, null);)

回答3:

Have you tried:

getLoaderManager().restartLoader(0, null, this);

in your activity, just after making changes on a database.

来源：https://stackoverflow.com/questions/9721937/android-spinner-does-not-update-after-change-of-dataset

标签

android

spinner

adapter

android-contentprovider

loader