網絡提供商和GPS提供商返回空值

Question

我想找到當前的緯度和當前位置的經度，但無論是網絡提供商和GPS提供商返回空值：

public class GPSTracker extends Service implements LocationListener { 

private final Context mContext; 

// flag for GPS status 
boolean isGPSEnabled = false; 

// flag for network status 
boolean isNetworkEnabled = false; 

// flag for GPS status 
boolean canGetLocation = false; 

Location location; // location 
double latitude; // latitude 
double longitude; // longitude 

// The minimum distance to change Updates in meters 
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters 

// The minimum time between updates in milliseconds 
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute 

// Declaring a Location Manager 
protected LocationManager locationManager; 

public GPSTracker(Context context) { 
    this.mContext = context; 
    getLocation(); 
} 

public Location getLocation() { 
    try { 
     locationManager = (LocationManager) mContext 
       .getSystemService(LOCATION_SERVICE); 

     // getting GPS status 
     isGPSEnabled = locationManager 
       .isProviderEnabled(LocationManager.GPS_PROVIDER); 

     // getting network status 
     isNetworkEnabled = locationManager 
       .isProviderEnabled(LocationManager.NETWORK_PROVIDER); 

     if (!isGPSEnabled && !isNetworkEnabled) { 
      Log.i("info", " no network provider is enabled"); 
     } else { 
      this.canGetLocation = true; 
      // First get location from Network Provider 
      if (isNetworkEnabled) { 
       locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,MIN_TIME_BW_UPDATES,MIN_DISTANCE_CHANGE_FOR_UPDATES, this); 
       Log.d("Network", "Network"); 
       if (locationManager != null) { 
        location = locationManager 
          .getLastKnownLocation(LocationManager.NETWORK_PROVIDER); 
        Log.i("location", ""+longitude); 
        if (location != null) { 
         latitude = location.getLatitude(); 
         longitude = location.getLongitude(); 
        } 
       } 
      } 
      // if GPS Enabled get lat/long using GPS Services 
      if (isGPSEnabled) { 
       if (location == null) { 
        locationManager.requestLocationUpdates(
          LocationManager.GPS_PROVIDER, 
          MIN_TIME_BW_UPDATES, 
          MIN_DISTANCE_CHANGE_FOR_UPDATES, this); 
        Log.d("GPS Enabled", "GPS Enabled"); 
        if (locationManager != null) { 
         location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER); 
        // location = locationManager.getLastKnownLocation("gps"); 
         Log.i("location,GPS", ""+location); 
         if (location != null) { 
          latitude = location.getLatitude(); 
          longitude = location.getLongitude(); 
         } 
        } 
       } 
      } 
     } 

    } catch (Exception e) { 
     e.printStackTrace(); 
    } 

    return location; 
} 

/** 
* Stop using GPS listener 
* Calling this function will stop using GPS in your app 
* */ 
public void stopUsingGPS(){ 
    if(locationManager != null){ 
     locationManager.removeUpdates(GPSTracker.this); 
    } 
} 

/** 
* Function to get latitude 
* */ 
public double getLatitude(){ 
    if(location != null){ 
     latitude = location.getLatitude(); 
    } 

    // return latitude 
    return latitude; 
} 

/** 
* Function to get longitude 
* */ 
public double getLongitude(){ 
    if(location != null){ 
     longitude = location.getLongitude(); 
    } 

    // return longitude 
    return longitude; 
} 

/** 
* Function to check GPS/wifi enabled 
* @return boolean 
* */ 
public boolean canGetLocation() { 
    return this.canGetLocation; 
} 

/** 
* Function to show settings alert dialog 
* On pressing Settings button will lauch Settings Options 
* */ 
public void showSettingsAlert(){ 
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext); 

    // Setting Dialog Title 
    alertDialog.setTitle("GPS is settings"); 

    // Setting Dialog Message 
    alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?"); 

    // On pressing Settings button 
    alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialog,int which) { 
      Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS); 
      mContext.startActivity(intent); 
     } 
    }); 

    // on pressing cancel button 
    alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialog, int which) { 
     dialog.cancel(); 
     } 
    }); 

    // Showing Alert Message 
    alertDialog.show(); 
} 

@Override 
public void onLocationChanged(Location location) { 
} 

@Override 
public void onProviderDisabled(String provider) { 
} 

@Override 
public void onProviderEnabled(String provider) { 
} 

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

@Override 
public IBinder onBind(Intent arg0) { 
    return null; 
} 

}

，並在主要活動，

 gps = new GPSTracker(MainActivity.this); 

    // check if GPS enabled 
    if(gps.canGetLocation()){ 

     double latitude = gps.getLatitude(); 
     double longitude = gps.getLongitude(); 

     // \n is for new line 
     Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show(); 
    }else{ 
     // can't get location 
     // GPS or Network is not enabled 
     // Ask user to enable GPS/network in settings 
     gps.showSettingsAlert(); 
    } 

但最後它顯示的經緯度爲0,0

Answer 1

它現在的工作：

我只是重寫onLocationChanges（Location location）方法和它的工作。

 @Override 
    public void onLocationChanged(Location location) { 
    if (location != null) 
    { 
     Log.i("SuperMap", "Location changed : Lat: " + location.getLatitude() + " Lng: " + location.getLongitude()); 
     latitude = location.getLatitude(); 
     longitude = location.getLongitude(); 
     Log.i("latitude,longitude", ""+latitude+","+longitude); 


    } 
}