Question

我只是想知道为什么当我尝试时，代码在同一个地方给了我很多标记获取用户当前位置？

如果有人知道如何在服务或AsyncTask中执行此操作，我无法在不同的类服务中执行此操作，这将对我的项目有很大帮助。

谢谢！

package toutel.testcarte;

import org.osmdroid.ResourceProxy;
import org.osmdroid.bonuspack.overlays.Marker;
import org.osmdroid.tileprovider.tilesource.TileSourceFactory;
import org.osmdroid.util.GeoPoint;
import org.osmdroid.views.MapController;
import org.osmdroid.views.MapView;
import org.osmdroid.views.overlay.ItemizedOverlay;
import org.osmdroid.views.overlay.OverlayItem;

import android.annotation.SuppressLint;
import android.app.Activity;
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.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

public class MainActivity extends Activity {

    private MapController mapController;
    private MapView mapView;
    private GeoPoint myposition;
    private ItemizedOverlay<OverlayItem> mMyLocationOverlay;
    private ResourceProxy mResourceProxy;

    @SuppressLint("NewApi")
    @SuppressWarnings("deprecation")
    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);
        mapView = (MapView) findViewById(R.id.mapview);
        mapController = (MapController) mapView.getController();
        GeoPoint myposition = new GeoPoint(48.856614, 2.3522219000000177);
        mapView.setTileSource(TileSourceFactory.MAPNIK);
        mapView.setBuiltInZoomControls(false);
        mapView.setMultiTouchControls(true);
        // mapController.animateTo(myposition);
        mapController.setZoom(13);
        mapController.setCenter(myposition);

        Context context = getApplicationContext();

        CharSequence text = "Activez votre GPS pour utiliser la localisation ";
        int duration = Toast.LENGTH_LONG;
        Toast toast = Toast.makeText(context, text, duration);
        toast.show();
    }

    public boolean onCreateOptionsMenu(Menu menu) {
         getMenuInflater().inflate(R.menu.main, menu);
         return true;
    }

    public boolean onOptionsItemSelected(MenuItem menu) {

         switch (menu.getItemId()) {

         case (R.id.fermer): {

              System.exit(0);
              break;
         }

         case (R.id.position): {

              LocationManager lm = (LocationManager)    getSystemService(Context.LOCATION_SERVICE);

              while (true) {

                   LocationListener mylocationlistener = new LocationListener() {

                       public void onLocationChanged(Location location) {

                           Context ctx = getApplicationContext();
                           GeoPoint myposition = new GeoPoint(
                                     location.getLatitude(), location.getLongitude());
                           mapController.animateTo(myposition);
                           mapController.setCenter(myposition);
                           mapController.setZoom(17);
                           Marker marker = new Marker(mapView);
                           marker.setPosition(myposition);
                           marker.setAnchor(Marker.ANCHOR_CENTER,
                                            Marker.ANCHOR_BOTTOM);
                                            mapView.getOverlays().add(marker);
                           mapView.invalidate();
                           try {
                               Thread.sleep(10 * 1000);
                           }
                           catch (InterruptedException e) {
                               e.printStackTrace();
                           }

                       }

                       @Override
                       public void onProviderDisabled(String provider) {
                            // TODO Auto-generated method stub
                       }

                       @Override
                       public void onProviderEnabled(String provider) {
                           // TODO Auto-generated method stub
                       }

                       @Override
                       public void onStatusChanged(String provider, int status, Bundle extras) {
                           // TODO Auto-generated method stub
                       }

                   };

                   lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 10000, 0, mylocationlistener);

                   break;
               }
           }

           case (R.id.itineraire): {

           }

        }
        return false;
    }

}

Answer 1

Multiple markers : why?

您将获得多个标记，因为每次更改位置时，您都会在地图上放置一个标记。即使位置变化太小。您正在放置标记。尝试放大您将看到所有标记都不在同样的立场。

我的建议在这里不需要服务。因为OnlocationChanged监听器自动完成你的工作。我已经编写了这个单一的类。现在在项目中你需要GPS坐标，只需实例化类对象并获得Latitude和经度。

  LocationSender loc = new LocationSender(YourClass.this);

当我将lat，lng（在LocationSender.java中）声明为静态时，我可以获得其值的任何位置。

  double latitude = LocationSender.lat;
  double longitude = LocationSender.lng;

LocationSender.java

public class LocationSender {
Context context;
LocationManager locationManager;
Location location;
static double lat,lng;
public LocationSender(Context ctx) {
context=ctx;
locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
}

// Acquire a reference to the system Location Manager
public void getNewLocation(Location location) throws JSONException 
{
String latLongString = "";
if (location != null) {
    this.location=location;
  lat= location.getLatitude();
   lng = location.getLongitude();
    latLongString = "Lat:" + String.valueOf(LocationActivity.lat) + "\nLong:" +        String.valueOf(LocationActivity.lng);
    Log.d("Location Found", latLongString);
   } else
  {
    location=null;
    latLongString = "No location found";
}
Toast.makeText(context, latLongString, Toast.LENGTH_LONG).show();
 }

 LocationListener locationListener = new LocationListener() {
 public void onLocationChanged(Location location) {
  // Called when a new location is found by the network location provider.
    try {
        getNewLocation(location);
    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
     }

   }



   public void onProviderEnabled(String provider) {

    Toast.makeText(context, "Provider: "+provider+" : Enabled", Toast.LENGTH_LONG).show();
    }

    public void onProviderDisabled(String provider) {

    Toast.makeText(context, "Provider: "+provider+" : disabled", Toast.LENGTH_LONG).show();
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
    Toast.makeText(context, "Provider: "+provider+" : status: "+status, Toast.LENGTH_LONG).show();

    }
    };    

    }

另外，请不要忘记在AndroidManifest.xml中添加权限

Answer 2

您真的需要针对位置管理员/位置服务的onLocationChanged()回调进行自定义实施吗？

否则，您可以查看OSMDroid的MyLocationNewOverlay类https://code.google.com/p/osmdroid/source/browse/trunk/osmdroid-android/src/main/java/org/osmdroid/views/overlay/mylocation/MyLocationNewOverlay.java?r=1220

还有一个名为MyLocationOverlay https://code.google.com/p/osmdroid/source/browse/trunk/osmdroid-android/src/org/osmdroid/views/overlay/MyLocationOverlay.java?r=902

的实现（不幸弃用）

在我的实现中，我使用它：

//declare variable; global - because I need reference elsewhere
private MyLocationOverlay self;

//somewhere in code
//'this' - is the context
//mapMainView - my mapView
self = new MyLocationOverlay(this, mapMainView);
self.enableMyLocation();
self.enableFollowLocation();

//add the overlay to the map and refresh the view
mapMainView.getOverlays().add(COUNT+1, self);//COUNT is the size of the List<Overlay> returned by  mapMainView.getOverlays(); this is just because I want my 'self' to be always the last overlay added
mapMainView.invalidate();//refresh the view

这会在地图上的某个位置放置一个默认图标，并在我移动时不断更新。

多个标记：为什么？

2 个答案: