获取当前位置从Android的后台服务问题 [英] Get Current Location From Android Background Service Issue

问题描述

我想开发基于位置的提醒应用程序。因此，我想使用Android的服务，为报复应用程序没有运行的当前位置。但我没有这样做。我设置计时器在Android的服务类，但我不知道如何在服务类中的当前位置。有什么问题 ？我得到了一些错误是这样的：

不能创建内螺纹的处理程序已经不叫尺蠖。prepare（）

 公共类TrackerService延伸服务{    双latShared;
    双lngShared;
    双latService;
    双lngService;
    私人的LocationManager流明;
    定时器定时器;
    处理程序处理程序;
    最终静态时间长= 15000;
    共享preferences mShared preFS;
    共享preferences.Editor米prefsEditor;    @覆盖
    公众的IBinder onBind（意向意图）{
        // TODO自动生成方法存根
        返回null;
    }    @覆盖
    公共无效的onCreate（）{
        mShared preFS = getShared preferences（locationXML，MODE_PRIVATE）;
        latShared =（双）mShared prefs.getFloat（纬度，0）;
        lngShared =（双）mShared prefs.getFloat（LNG，0）;
        定时器=新定时器（）;
        timer.schedule（新的TimerTask（）{
            @覆盖
            公共无效的run（）{
                LocationUpdates（）;
            }
        } 0，时间）;    }    公共无效LocationUpdates（）{
        locListener locList =新locListener（）;
        LM =（的LocationManager）getSystemService（Context.LOCATION_SERVICE）;
        lm.requestLocationUpdates（LocationManager.GPS_PROVIDER，0，0，locList）;
    }    @覆盖
    公共无效的onDestroy（）{
        //lm.removeUpdates(this）;
        timer.cancel（）;
    }    公共类locListener实现LocationListener的{        @覆盖
        公共无效onLocationChanged（地点）{
            latService = location.getLatitude（）;
            lngService = location.getLongitude（）;
        }        @覆盖
        公共无效onProviderDisabled（字符串提供商）{}        @覆盖
        公共无效onProviderEnabled（字符串提供商）{}        @覆盖
        公共无效onStatusChanged（字符串提供商，INT地位，捆绑演员）{}
    }}
 

解决方案

LocationManager.requestLocationUpdates 应该作为 UI线程运行其<一个href=\"http://developer.android.com/reference/android/location/LocationManager.html#requestLocationUpdates%28long,%20float,%20android.location.Criteria,%20android.app.PendingIntent%29\"相对=nofollow>兄弟方法定义。在另一方面的TimerTask 引入了一个新的线程来卸载它的执行。

不过，如果你不使用的新工艺，为您服务，然后只需拨打 LocationUpdates（）如下：

  @覆盖
保护无效的onCreate（）{
    mShared preFS = getShared preferences（locationXML，MODE_PRIVATE）;
    latShared =（双）mShared prefs.getFloat（纬度，0）;
    lngShared =（双）mShared prefs.getFloat（LNG，0）;    最后的处理程序H =新的处理程序（）;
    h.post（新的Runnable（）{
        @覆盖
        公共无效的run（）{
            LocationUpdates（）;
            h.postDelayed（这一点，TIME）;
        }
    }）;
}
 

或，如果你不希望使用的处理程序然后简单地升级你的 requestLocationUpdates 如下：

  lm.requestLocationUpdates（LocationManager.GPS_PROVIDER，0，0，locList，getMainLooper（））;
 

在上述情况下， getMainLooper（）将派遣从UI线程更新自己的位置。

I want to develop location based reminder app. Therefore I want to use android service for get current location even app is not running. But I didn't do. I set timer in android service class but I don't know how to get current location in service class. What is the problem ? I got some error like this:

can't create handler inside thread that has not called looper.prepare()

public class TrackerService extends Service {

    double latShared;
    double lngShared;
    double latService;
    double lngService;
    private LocationManager lm;
    Timer timer;
    Handler handler;
    final static long TIME = 15000;
    SharedPreferences mSharedPrefs;
    SharedPreferences.Editor mPrefsEditor;



    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }

    @Override
    public void onCreate() {
        mSharedPrefs = getSharedPreferences("locationXML", MODE_PRIVATE);
        latShared = (double)mSharedPrefs.getFloat("lat", 0);
        lngShared = (double)mSharedPrefs.getFloat("lng", 0);
        timer = new Timer();
        timer.schedule(new TimerTask(){
            @Override
            public void run(){
                LocationUpdates();
            }
        },0,TIME);

    }    

    public void LocationUpdates(){
        locListener locList = new locListener();
        lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);   
        lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locList);
    }

    @Override
    public void onDestroy() {
        //lm.removeUpdates(this);
        timer.cancel();
    }

    public class locListener implements LocationListener{

        @Override
        public void onLocationChanged(Location location) {
            latService = location.getLatitude();
            lngService = location.getLongitude();
        }

        @Override
        public void onProviderDisabled(String provider) {}

        @Override
        public void onProviderEnabled(String provider) {}

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {}


    }

}

解决方案

LocationManager.requestLocationUpdates is supposed to run on UI thread as its sibling method defines. On the other hand TimerTask introduces a new thread to offload its execution.

However, if you are not using a new process for your service then simply call LocationUpdates() as below:

@Override
protected void onCreate() {
    mSharedPrefs = getSharedPreferences("locationXML", MODE_PRIVATE);
    latShared = (double)mSharedPrefs.getFloat("lat", 0);
    lngShared = (double)mSharedPrefs.getFloat("lng", 0);

    final Handler h = new Handler();
    h.post(new Runnable() {
        @Override
        public void run() {
            LocationUpdates();
            h.postDelayed(this, TIME);
        }
    });
}

OR, if you don't want to use handler then simply upgrade your requestLocationUpdates as below:

lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locList, getMainLooper());

In above case, getMainLooper() will dispatch your location updates from UI thread.

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