爲什麼onLocationChanged（）在不可預知的時間觸發？

我瞄準了Android 1.6爲什麼onLocationChanged（）在不可預知的時間觸發？

的的LocationManager和聽衆是服務

requestLocationUpdates（）作爲中實現如下：

   locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 
                 //3 mins 
                 Constants.LOCATION_UPDATE_PERIOD_MSEC, 
                 //no distance is necessary 
                 0, 
                 locationListener);

位置管理器和監聽如下實施：

locationManager = (LocationManager) getSystemService(GPS_Service.this.LOCATION_SERVICE);  

    locationListener = new GPSlocListener(mHandler, Constants.LOCATION_UPDATE_TIME, true);

我實施的LocationListener：

public class GPSlocListener implements LocationListener 
{ 
    //constructor 
    public GPSlocListener(Handler parentMsgHandler, long timeBetweenLocationEvents, boolean accuracyOverride) 
    { 
    //store passed-in values in member variables 
    } 

    public void onLocationChanged(Location loc) 
    { 
     Log.d(TAG, "onLocationChanged() called."); 

     //process the data and send the location to the parentMsgHandler 
    } 

    public void onProviderDisabled(String provider) 
    { 
     // TODO Auto-generated method stub 
    } 

    public void onProviderEnabled(String provider) 
    { 
     // TODO Auto-generated method stub 
    } 

    public void onStatusChanged(String provider, int status, Bundle extras) 
    { 
     // TODO Auto-generated method stub 
    } 
}

有時onLocationChanged以3分鐘間隔觸發，有時至少10分鐘可以通過（可能更長）。我會監視應用程序，並定期顯示小衛星圖標。但是，不能可靠地調用onLocationChanged（）。

一些記錄信息：

04-07 22:08:58.945: DEBUG/GpsLocationProvider(107): Acquiring wakelock 
04-07 22:08:59.186: DEBUG/libgps(107): report status : 3 
04-07 22:09:05.155: DEBUG/dalvikvm(228): GC_EXPLICIT freed 13 objects/536 bytes in 88ms 
04-07 22:09:14.997: DEBUG/libgps(107): PDSM_PD_EVENT_UPDATE_FAILURE 
04-07 22:09:15.005: DEBUG/libgps(107): report status : 2 
04-07 22:09:15.025: DEBUG/libgps(107): report status : 1 
04-07 22:09:16.035: DEBUG/libgps(107): report status : 4 
04-07 22:09:16.035: DEBUG/libgps(107): report status : 3 
04-07 22:09:16.035: DEBUG/libgps(107): report status : 3 
04-07 22:09:31.065: DEBUG/libgps(107): report status : 2 
04-07 22:09:31.125: DEBUG/libgps(107): report status : 1 
04-07 22:09:32.145: DEBUG/libgps(107): report status : 4 
04-07 22:09:32.145: DEBUG/libgps(107): report status : 3 
04-07 22:09:32.145: DEBUG/libgps(107): report status : 3 
04-07 22:09:47.165: DEBUG/libgps(107): report status : 2 
04-07 22:09:47.185: DEBUG/libgps(107): report status : 1 
04-07 22:09:48.195: DEBUG/libgps(107): report status : 4 
04-07 22:09:48.381: DEBUG/libgps(107): report status : 3 
04-07 22:09:48.381: DEBUG/libgps(107): report status : 3 
04-07 22:09:48.615: DEBUG/LocationManagerService(107): CdmaCellLocation Available 
04-07 22:09:48.625: VERBOSE/AlarmManager(107): Adding Alarm{46208250 type 2 com.google.android.apps.maps} Dec 13 12:46:54 pm 
04-07 22:09:51.855: DEBUG/LocationManagerService(107): CdmaCellLocation Available 
04-07 22:09:51.865: VERBOSE/AlarmManager(107): Adding Alarm{461e4e88 type 2 com.google.android.apps.maps} Dec 13 12:46:54 pm 
04-07 22:09:56.895: DEBUG/dalvikvm(206): GC_EXPLICIT freed 172 objects/6912 bytes in 58ms 
04-07 22:09:58.915: VERBOSE/AlarmManager(107): Alarm triggering: Alarm{464f6cc8 type 2 android} 
04-07 22:09:58.925: DEBUG/GpsLocationProvider(107): ALARM_TIMEOUT 
04-07 22:09:58.925: DEBUG/GpsLocationProvider(107): stopNavigating 
04-07 22:09:58.925: DEBUG/libgps(107): qct_gps_stop 
04-07 22:09:58.925: DEBUG/libgps(107): report status : 2 
04-07 22:09:58.925: VERBOSE/AlarmManager(107): Adding Alarm{46540430 type 2 android} Jan 01 05:22:56 am 
04-07 22:10:00.965: DEBUG/libgps(107): report status : 4 
04-07 22:10:00.965: DEBUG/GpsLocationProvider(107): Releasing wakelock

和權限：

<uses-sdk android:minSdkVersion="4" /> 

<uses-permission android:name="android.permission.INTERNET" /> 
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> 
<uses-permission android:name="android.permission.LOCATION" /> 
<uses-permission android:name="android.permission.VIBRATE" /> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

，並給你一個想法，這是一個典型的結果：

04-07 21:42:46.985: DEBUG/GPSlocListener(2582): onLocationChanged() called. 
04-07 21:42:58.515: DEBUG/GPSlocListener(2582): onLocationChanged() called. 
04-07 21:45:14.825: DEBUG/GPSlocListener(2582): onLocationChanged() called. 
04-07 21:48:14.865: DEBUG/GPSlocListener(2582): onLocationChanged() called. 
04-07 21:48:26.205: DEBUG/GPSlocListener(2582): onLocationChanged() called. 
04-07 21:48:57.815: DEBUG/GPSlocListener(2582): onLocationChanged() called. 
04-07 21:54:30.995: DEBUG/GPSlocListener(2582): onLocationChanged() called. 
04-07 21:54:42.375: DEBUG/GPSlocListener(2582): onLocationChanged() called. 
04-07 21:54:54.395: DEBUG/GPSlocListener(2582): onLocationChanged() called.

來源

2011-04-08 Someone Somewhere

的onLocationChanged會當設備的位置改變時觸發。如果你坐在一個地方並且位置沒有改變，那麼onLocationChanged可能不會被觸發。那麼情況就是這樣，那麼你的程序工作正常，LocationManager也按預期行事。

嘗試更改Log.d以顯示烤麪包，因爲您的位置已更改並嘗試走動或移動您的位置。隨着位置的變化，您會看到更新後的位置敬酒。嘗試減少測試用例的最小間隔;）。另外請記住，如果您在建築物中時獲取位置，GPS位置將不準確。

Achievement。

來源

2011-04-08 05:44:32 achie

哦，這對我來說是個壞消息:-(我希望requestLocationUpdates（）不會考慮距離，因爲我傳入一個0作爲距離參數。 – 2011-04-08 06:43:23

我發現這篇文章，它解釋了一些東西太：http://www.android10.org/index.php/articleslocationmaps/294-how-locationlistener-works-in-android – 2011-04-09 01:29:43

〜「如果你坐在一個地方，位置沒有改變，那麼onLocationChanged將不會被觸發「，這是不正確的，我已經測試了它坐在一個地方，並且該設備可能仍然認爲該位置改變了！ – 2013-11-12 17:07:16

爲什麼onLocationChanged（）在不可預知的時間觸發？

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