2013-08-05 51 views
0

我正在調查一個android軟件的問題,在後臺將設備的位置記錄到日誌文件中。該代碼是這樣的:onStartCommand中的requestLocationUpdates導致GPS停止響應?

package com.otpc.auto; 

import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import android.app.Service; 
import android.content.Context; 
import android.content.Intent; 
import android.location.Location; 
import android.location.LocationListener; 
import android.location.LocationManager; 
import android.os.Bundle; 
import android.os.Environment; 
import android.os.IBinder; 
import android.os.Looper; 
import android.util.Log; 
import android.widget.Toast; 

public class LocationUpdate extends Service { 
    private String TAG = "LocationUpdate"; 
    private LocationManager loc; 
    private class CustomLocationListener implements LocationListener { 
     public void onStatusChanged(String provider, int status, Bundle extras) { 
     } 
     public void onProviderEnabled(String provider) { 
     } 
     public void onProviderDisabled(String provider) { 
     } 
     public void onLocationChanged(Location location) { 
      writeLocationData(location); 
     } 
    } 
    @Override 
    public IBinder onBind(Intent intent) { 
     return null; 
    } 
    @Override 
    public int onStartCommand(Intent intent, int flags, int startId) { 
     Toast.makeText(this, "Location Update service has been started", Toast.LENGTH_SHORT).show(); 
     loc = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
     loc.requestLocationUpdates(LocationManager.GPS_PROVIDER, 60 * 60 * 1000, 100, 
       new CustomLocationListener(), 
       Looper.myLooper()); 
     loc.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 60 * 60 * 1000, 100, 
       new CustomLocationListener(), 
       Looper.myLooper()); 
     return Service.START_STICKY; 
    } 
    private void writeLocationData(Location location){ 
     final double latitude = location.getLatitude(); 
     final double lon = location.getLongitude(); 
     new Thread(){ 
      public void run() { 
       try { 
        FileOutputStream latitudeFile = new FileOutputStream(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) + "/latitude.txt"); 
        latitudeFile.write(String.valueOf(latitude).getBytes()); 
        latitudeFile.close(); 
        FileOutputStream longitudeFile = new FileOutputStream(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) + "/longitude.txt"); 
        longitudeFile.write(String.valueOf(lon).getBytes()); 
        longitudeFile.close(); 
       } catch (FileNotFoundException e) { 
        e.printStackTrace(); 
       } catch (IOException e) { 
        e.printStackTrace(); 
       } 
      }; 
     }.start(); 
    } 
} 

寄存器後以此爲啓動服務,其他應用程序可以不再使用GPS服務。使用GPS Tester應用程序測試GPS就像設備沒有GPS一樣給出結果。只有在我們從設備中刪除此應用程序後,GPS才能正常運行。

上述代碼有什麼問題。我不是Android的專家,但從我所看到的,我無法發現代碼中的任何異常。

謝謝。

回答

0

我不記得究竟是什麼原因,但我以前遇到過這個問題。我認爲問題在於請求的更新頻率比設備可以處理的更高(或者更低)。嘗試使用請求中的數字進行操作,看看事情是否有所改善。

0

嘗試消除Looper.myLooper()註冊爲位置回調時:

@Override 
public int onStartCommand(Intent intent, int flags, int startId) { 
    Toast.makeText(this, "Location Update service has been started", Toast.LENGTH_SHORT).show(); 
    loc = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
    loc.requestLocationUpdates(LocationManager.GPS_PROVIDER, 60 * 60 * 1000, 100, 
      new CustomLocationListener()); 
    loc.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 60 * 60 * 1000, 100, 
      new CustomLocationListener()); 
    return Service.START_STICKY; 
} 

如果您註冊Looper.myLooper()你註冊的系統線程調用onStartCommand()使用它的消息隊列實現回調機制,這可能是造成問題在後臺。