姬長信(Redy)

android – 如何从服务到活动获取数据


在我的应用程序中,我有一项活动和服务……
该服务将广播从GPS数据收集的消息……
活动应该接收广播消息并更新UI …

我的代码

public class LocationPollerDemo extends Activity {
    private static final int PERIOD = 10000; // 30 minutes
    private PendingIntent pi = null;
    private AlarmManager mgr = null;
    private double lati;
    private double longi;
    private ServiceReceiver serviceReceiver;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        mgr = (AlarmManager) getSystemService(ALARM_SERVICE);

        Intent i = new Intent(this, LocationPoller.class);

        i.putExtra(LocationPoller.EXTRA_INTENT, new Intent(this, ServiceReceiver.class));
        i.putExtra(LocationPoller.EXTRA_PROVIDER, LocationManager.GPS_PROVIDER);

        pi = PendingIntent.getBroadcast(this, 0, i, 0);
        mgr.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime(), PERIOD, pi);

        DebugLog.logTrace("On Create Demo");
        Toast.makeText(this, "Location polling every 30 minutes begun", Toast.LENGTH_LONG).show();
        serviceReceiver = new ServiceReceiver();
        IntentFilter filter = new IntentFilter("me");
        this.registerReceiver(serviceReceiver, filter);
    }

    class ServiceReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            File log = new File(Environment.getExternalStorageDirectory(), "Location2.txt");
            DebugLog.logTrace(Environment.getExternalStorageDirectory().getAbsolutePath());

            try {
                BufferedWriter out = new BufferedWriter(new FileWriter(log.getAbsolutePath(), log.exists()));

                out.write(new Date().toString());
                out.write(" : ");

                Bundle b = intent.getExtras();
                Location loc = (Location) b.get(LocationPoller.EXTRA_LOCATION);
                String msg;

                if (loc == null) {
                    loc = (Location) b.get(LocationPoller.EXTRA_LASTKNOWN);

                    if (loc == null) {
                        msg = intent.getStringExtra(LocationPoller.EXTRA_ERROR);
                    } else {
                        msg = "TIMEOUT, lastKnown=" + loc.toString();
                    }
                } else {
                    msg = loc.toString();
                }

                if (msg == null) {
                    msg = "Invalid broadcast received!";
                }

                out.write(msg);
                out.write("/n");
                out.close();
            } catch (IOException e) {
                Log.e(getClass().getName(), "Exception appending to log file", e);
                DebugLog.logException(e);
            }
        }
    }
}

当我使用此代码时,它无法正常工作……
我在单独的文件中使用ServiceReceiver类工作正常….
请告诉我…!!