如何在SyncAdapter完成同步后刷新Android ListView

Question

如何在SyncAdapter完成同步后刷新Android ListView

androidlistviewsynchronization

3

我已经扩展了一个AbstractThreadedSyncAdapter，并通过代码每x分钟或手动请求同步来自动同步与我的服务器的数据。它完美地工作。

现在下一步是自动更新包含消息和另一个包含指定作业的ListView。

我找到的示例都假定您从同一Activity中更改数据集，或者您以其他方式访问ListView绑定到的数据库游标。不幸的是对于Android Sync Adapter而言，情况并非如此。它在后台运行，没有任何有用的参考资料，据我所知。

我的SyncAdapter:

public class VttSyncAdapter extends AbstractThreadedSyncAdapter {
    private final AccountManager mAccountManager;

    public VttSyncAdapter(Context context, boolean autoInitialize) {
        super(context, autoInitialize);
        mAccountManager = AccountManager.get(context);
    }

    @Override
    public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
        Log.d("Vtt", "onPerformSync for account[" + account.name + "]");
        try 
        {         
            //GET SOME DATA FROM WEBSERVICE AND INSERT INTO SQLITE DB
        } catch (IOException e) {
            e.printStackTrace();
        }

        //WHAT WOULD ONE DO HERE TO ALERT THE LISTVIEW THAT IT SHOULD REFRESH?

        } catch (Exception e) {
            e.printStackTrace();

    }

    public String getsharedresourcestring(String key)
    {
        Context context = getContext();
        SharedPreferences sharedPref = context.getSharedPreferences(context.getString(R.string.preference_file_key), MODE_PRIVATE);
        return sharedPref.getString(key,null);
    }

}

我日程表的片段代码：

public class ScheduleFragment extends Fragment {
    private ListView listView;
    private List<DeliveryScheduleEntryModel> schedules;


    public ScheduleFragment() {
        // Required empty public constructor
    }

    public static ScheduleFragment newInstance(String param1, String param2) {
        ScheduleFragment fragment = new ScheduleFragment();
        Bundle args = new Bundle();
        //args.putString(ARG_PARAM1, param1);
        //args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            //mParam1 = getArguments().getString(ARG_PARAM1);
            //mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View ret = inflater.inflate(R.layout.fragment_schedule, container, false);

        listView = (ListView) ret.findViewById(R.id.listViewSchedule);

        //GET OUR DATA
        Activity activity = this.getActivity();
        ContentResolver contentResolver = activity.getContentResolver();
        schedules = getSchedule(contentResolver);

        DeliveryScheduleEntryModelList customList = new DeliveryScheduleEntryModelList(activity, schedules);

        listView.setAdapter(customList);
        return ret;
    }

    public List<DeliveryScheduleEntryModel> getSchedule(ContentResolver cr)
    {
        Context context = getContext();
        VttDataSource db = new VttDataSource(context);
        db.open();
        List<DeliveryScheduleEntryModel> ret = db.getAllDeliveryScheduleEntryModel();
        db.close();

        return ret;
    }
}

- Captain Kenpachi

1个回答

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- Bö macht Blau · Accepted Answer

//如何提醒ListView应该刷新？

可以像下面这样发送一个本地广播：

Intent intent = new Intent();
intent.setAction("com.your_package.name.REFRESH_LIST");
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);

让带有 ListView 的 Fragment 声明一个 BroadcastReceiver：

private BroadcastReceiver myReceiver = new BroadcastReceiver()
{
    @Override
    public void onReceive(Context context, Intent intent)
    {

        String sAction = intent.getAction();
        if ("com.your_package.name.REFRESH_LIST".equals(sAction) )
        {
            // update the ListView here
        }
    }
}

在onAttach()中注册广播接收器 BroadcastReceiver：

IntentFilter myFilter = new IntentFilter();
myFilter.addAction("com.your_package.name.REFRESH_LIST");
LocalBroadcastManager.getInstance(this).registerReceiver(myReceiver, myFilter);

不要忘记在onDetach()中取消注册。

LocalBroadcastManager.getInstance(this).unregisterReceiver(myReceiver);

这样，只要Fragment与Activity连接，Fragment将会接收到更新消息。

另一种选择是使用某种类型的事件总线（如greenrobot、Otto等）。