android-位置應用程序優化

Question

我創建了一個位置應用程序，它將在我的設備上的google maps api中顯示當前位置，但我在使用網絡提供商和gps提供商時感到困惑。

我希望我的應用程序在應用程序打開時使用網絡提供程序，因此它可以快速指向位置。那麼它應該搜索GPS提供商，一旦GPS可用，那麼它應該使用GPS提供商。在運行應用程序時，如果我鬆動GPS連接，它應該返回到網絡提供商，並等待GPS可用。

我的源代碼是

public class MyGoogleMap1Activity extends MapActivity 
{ 
    private static final long min_distance = 1; // in Meters 
    private static final long min_time = 1000; // in Milliseconds 
    protected LocationManager locationManager; 
    protected MyLocationListener locationListener; 
    HelloItemizedOverlay itemizedoverlay; 
    List<Overlay> mapOverlays; 
    MapView mapView; 

    /** Called when the activity is first created. */ 
    @Override public void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     try 
     { 
      mapView = (MapView) findViewById(R.id.mapview); 
      mapView.setBuiltInZoomControls(true); 
      mapOverlays = mapView.getOverlays(); 
      Drawable drawable = this.getResources().getDrawable(R.drawable.google_maps_pin); 
      itemizedoverlay = new HelloItemizedOverlay(drawable); 
      locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
      locationListener = new MyLocationListener(); 
      locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 
      min_time,min_distance ,locationListener); 
     } 
     catch(Exception e) 
     { 
      Toast.makeText(MyGoogleMap1Activity.this, e.getMessage(), Toast.LENGTH_LONG).show(); 
     } 
    } 

    @Override protected boolean isRouteDisplayed() 
    { 
     return false; 
    } 

    private class MyLocationListener implements LocationListener 
    { 
     public void onLocationChanged(Location location) 
     { 
      try 
      { 
       if (location != null) 
       { 
        int lat = (int) (location.getLatitude() * 1E6); //coordinates are in microdegrees 
        int lng = (int) (location.getLongitude() * 1E6); 
        GeoPoint point = new GeoPoint(lat, lng); 
        OverlayItem overlayitem = new OverlayItem(point, "", ""); 
        itemizedoverlay.addOverlay(overlayitem); 
        mapOverlays.add(itemizedoverlay); 
        MapController myMapController = mapView.getController(); 
        myMapController.animateTo(point); 
        myMapController.setZoom(16); 
       } 
       String message = String.format("Current Location \n Longitude: %1$s \n Latitude: 2$s",location.getLongitude(), location.getLatitude()); 
       Toast.makeText(MyGoogleMap1Activity.this,message, Toast.LENGTH_LONG).show(); 
      } 
      catch(Exception e) 
      { 
       Toast.makeText(MyGoogleMap1Activity.this, e.getMessage(), Toast.LENGTH_LONG).show(); 
      } 
     } 

     public void onStatusChanged(String provider, int status, Bundle extras) 
     { 
      Toast.makeText(MyGoogleMap1Activity.this,"Status Changed",Toast.LENGTH_LONG).show(); 
     } 

     public void onProviderDisabled(String s) 
     { 
      Toast.makeText(MyGoogleMap1Activity.this,"Provider disabled by the user. GPS turned off",Toast.LENGTH_LONG).show(); 
     } 

     public void onProviderEnabled(String s) 
     { 
      Toast.makeText(MyGoogleMap1Activity.this,"Provider enabled by the user. GPS turned  on",Toast.LENGTH_LONG).show(); 
     } 

    } 

} 

Answer 1

這裏是如何將不同位置提供

Remeber，網絡提供商是非常不準確的之間變戲法的article by Google。它依賴於手機信息。與10到50米的GPS精度相比，網絡提供商的精度爲100到3000米。 GPS提供商衛星可見度在建築物或茂密森林/城市地區受損。然而，自推出輔助GPS後，您不必依賴衛星的可視性。 GPS提供商將永遠是更好的選擇。