在后台持续更新位置

Posted 2023-04-14

【中文标题】在后台持续更新位置

【英文标题】：Continuous location updates in background

【发布时间】：2014-03-10 16:53:45

【问题描述】：

我正在开发一个应用程序，它将从后台服务连续发送位置更新。我尝试了以下代码。

public class LocationService extends Service implements LocationListener,
GooglePlayServicesClient.ConnectionCallbacks,
GooglePlayServicesClient.OnConnectionFailedListener 
    LocationRequest mLocationRequest;
    LocationClient mLocationClient;
    @Override
     public void onCreate() 
     //creating log file in mobile
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Service created:", com.example.locationservice.Constants.LOG_FILE);

      mLocationRequest = LocationRequest.create();
      mLocationRequest.setInterval(5*1000);
      mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    //  mLocationRequest.setFastestInterval(5*1000);
      mLocationClient = new LocationClient(getApplicationContext(), this,this);
      mLocationClient.connect();

     
    @Override
     public void onStart(Intent intent, int startId) 
      int start = Service.START_STICKY;
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Service Started:", com.example.locationservice.Constants.LOG_FILE);

     

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) 
        // TODO Auto-generated method stub
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Connection to client failed", com.example.locationservice.Constants.LOG_FILE);
        this.stopSelf();

    

    @Override
    public void onConnected(Bundle arg0) 
        // TODO Auto-generated method stub
        Log.i("info", "Location Client is Connected");
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Location Client Connectd:", com.example.locationservice.Constants.LOG_FILE);
        //checking for locaton enabled or not
        if(Util.isLocationEnabled(getApplicationContext()))
        //checking for internet available or not
            if(Util.isInternetOn(getApplicationContext()))
                mLocationClient.requestLocationUpdates(mLocationRequest, this);
            else
              Log.i("info", "Internet not available");
                appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Internet not available", com.example.locationservice.Constants.LOG_FILE);
                this.stopSelf();
            
          else
            Log.i("info", "Location Acess disabled");
            appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Location Acess disabled", com.example.locationservice.Constants.LOG_FILE);
            this.stopSelf();
          
          Log.i("info", "Service Connect status :: " + isServicesConnected());

    

    @Override
    public void onDisconnected() 
        // TODO Auto-generated method stub
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Location Client DisConnectd:", com.example.locationservice.Constants.LOG_FILE);
        Log.i("info", "Location Client is DisConnected");

    

    @Override
    public void onLocationChanged(Location location) 
        // TODO Auto-generated method stub
        double latitude = location.getLatitude();
          double longitude = location.getLongitude();
            appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Location Changed:", com.example.locationservice.Constants.LOG_FILE);
          Log.i("info", "Latitude :: " + latitude);
          Log.i("info", "Longitude :: " + longitude);
          if(Util.isInternetOn(getApplicationContext()))
          //sending location details
          sendLocation(location);
          else
              this.stopSelf();
              Log.i("info", "Internet not available");
                appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Internet not available", com.example.locationservice.Constants.LOG_FILE);
          
    

    @Override
    public IBinder onBind(Intent intent) 
        // TODO Auto-generated method stub
        return null;
    
    @Override
     public void onDestroy() 
      // TODO Auto-generated method stub
      Log.i("info", "Service is destroyed");
      mLocationClient.removeLocationUpdates(this);  
        appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Service Destroyed:", com.example.locationservice.Constants.LOG_FILE);
      super.onDestroy();
     
    private boolean isServicesConnected() 
          // Check that Google Play services is available
          int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(LocationService.this);
          // If Google Play services is available
          if (ConnectionResult.SUCCESS == resultCode)            
           return true;
           else 
           return false;
          
         

但onLocationChanged 仅在我打开内置地图应用程序时调用。否则，它不会更新位置详细信息。 我从使用警报服务的活动中启动了此服务。 alarmManager 每一分钟触发一次。谁能告诉我为什么 onLocationChanged 没有连续调用。

提前致谢。

【问题讨论】：

您确定设备有时间获得 GPS 首次定位（如您所期望的高精度）。如果它一直困扰着您，您可以从这个答案***.com/questions/19365035/… 中尝试我的代码。已经在多个场合成功使用过。

【参考方案1】：

试试这个：

@Override
 public void onCreate() 
 //creating log file in mobile
    appendLog(DateFormat.getDateTimeInstance().format(new Date()) + ": Service created:", com.example.locationservice.Constants.LOG_FILE);

  mLocationClient = new LocationClient(getApplicationContext(), this,this);
 

将您的 onStart 替换为：

@Override
public int onStartCommand(Intent intent, int flags, int startId) 
mLocationClient.connect();

和：

@Override
public void onConnected(Bundle arg0) 
mLocationRequest = LocationRequest.create();
mLocationRequest.setInterval(5*1000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
mLocationClient.requestLocationUpdates(mLocationRequest, this);

调用你的服务：

startService(yourServiceIntent);

你也可以查看我的代码here

【讨论】：

后台运行正常吗？在后台运行时服务在 45 分钟后不会停止？

【参考方案2】：

它在后台工作正常吗？在后台运行时服务在 45 分钟后没有停止？ – 诺曼 2015 年 11 月 3 日 6:18

这是一个很好的评论。在我的项目中，我对位置更新有一些问题。 45 分钟后它真的停止了。

我的服务是前台。我用

StartForeground(ServicesId.Push, 通知);

而且我每 45 分钟醒来一次位置更新

_timer = new Timer(); _timer.Schedule(new TimerTaskTrek(this), 45 * 60 * 1000 + 10 * 1000, 45 * 60 * 1000 + 10 * 1000);

在定时器任务中

试试

Looper.Prepare();

捕获（异常 e）

_client = new >GoogleApiClient.Builder(this).AddApi(LocationServices.API) .AddConnectionCallbacks(这个) .AddOnConnectionFailedListener(这个) .Build();

_client.Connect();

这很简单，而且效果很好。 享受