android – 如何从FragmentActivity更新ListFragment中的ListView？

我正在使用FragmentActivity中的ListFragment与SimpleCursorAdapter和修改的CursorLoader.修改的CursorLoader只是发出rawQueries – 没有其他更改.

在FragmentActivity中的某个时刻,我需要重新获取ListFragment中的ListView的数据/游标.

我怎样才能做到这一点？

提前谢谢了.

这是FragmentActivity调用ListFragment中的一个方法：

public class ActivityList extends FragmentActivity {

    @Override
    protected void onActivityResult(final int requestCode,final int resultCode,final Intent intent) {
        ...
        processUpdateList();
    }

    ...

    private void processUpdateList() {
        Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.fragmentlist);
        if (fragment != null) {
            ((FragmentList) fragment).requeryList();
        }
    }
}

这里是ListFragment,该方法应该启动ListView的重新查询,重新加载或重新绘制. ListView.invalidate()没有帮助 – 它没有更改显示的数据.

public class FragmentList extends ListFragment implements LoaderManager.LoaderCallbacks<Cursor> {

    private SimpleCursorAdapter adapter;
    private Context             context;
    private ListView            listView;

    public void requeryList() {
    // listView.invalidate(); didn't re-query
        // Todo: How???
    }

    @Override
    public void onActivityCreated(final Bundle bundle) {
        super.onActivityCreated(bundle);

        context = getActivity().getApplicationContext();

        listView = getListView();

        getActivity().getSupportLoaderManager().initLoader(MyConstants.LDR_TABLE1LIST,null,this);

        adapter = new SimpleCursorAdapter(context,R.layout.fragmentlist_row,new String[] { Table1.DESCRIPTION },new int[] { R.id.fragmentlist_row_description },CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
        setlistadapter(adapter);
        setListShown(false);

        listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
    }

    @Override
    public Loader<Cursor> onCreateLoader(final int id,final Bundle bundle) {
        MyCursorLoader loader = null;

        switch (id) {
            case MyConstants.LDR_TABLE1LIST:
                loader = new MyCursorLoader(context,MysqLiteOpenHelper.TABLE1_FETCH,null);
                break;
        }

        return loader;
    }

    @Override
    public void onLoaderReset(final Loader<Cursor> loader) {
        adapter.swapCursor(null);
    }

    @Override
    public void onLoadFinished(final Loader<Cursor> loader,final Cursor cursor) {
        adapter.swapCursor(cursor);

        setListShown(true);
    }
}

解决方法

尝试调用方法restartLoader(MyConstants.LDR_TABLE1LIST,this);在您的requeryList()方法中提供的LoaderManager.