Question

我现在正在推进与Google地图服务相关的项目。我想在我的地图中指出我当前的位置。为此，我有一个使用itemizedoverlay的想法。我在Geopoint的帮助下检索当前位置。但是当我在我的代码中使用itemizedoverlay时，无法获取位置，我在OnCreate方法中使用它。如果我将其移动到OnLocationChanged方法，则itemizedoverlay将不会选择GeoPoint（point）并以错误结束，并且在当前条件下，应用程序将被压缩。

        MapView mapView;
    Location location;
    LocationManager locationmanager;
    LocationListener locationlistener; 

        public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

      mapView = (MapView) findViewById(R.id.mapView);
      mapView.setTraffic(true);
      mapView.setBuiltInZoomControls(true);

        //locationmanager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);  
   // locationlistener = new GPSLocationListener();
      //  locationmanager.requestLocationUpdates(LocationManager.GPS_PROVIDER 0,0,locationlistener);                                                                                         

      GeoPoint point = new GeoPoint(
                (int) (location.getLatitude() * 1E6), 
                (int) (location.getLongitude() * 1E6));

            Toast.makeText(getBaseContext(), 
                "Latitude: " + location.getLatitude() + 
                " Longitude: " + location.getLongitude(), 
                Toast.LENGTH_SHORT).show();

      List<Overlay> mapOverlays = mapView.getOverlays();
      Drawable drawable = this.getResources().getDrawable(R.drawable.icon);


          HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(drawable,this);
          OverlayItem overlayitem = new OverlayItem(point,"","" );
          itemizedoverlay.addOverlay(overlayitem);
          mapOverlays.add(itemizedoverlay);

}

/*      private class GPSLocationListener implements LocationListener 
      {
        @Override
        public void onLocationChanged(Location location) {
          if (location != null) {
            GeoPoint point = new GeoPoint(
                (int) (location.getLatitude() * 1E6), 
                (int) (location.getLongitude() * 1E6));

            Toast.makeText(getBaseContext(), 
                "Latitude: " + location.getLatitude() + 
                " Longitude: " + location.getLongitude(), 
                Toast.LENGTH_SHORT).show();

            OverlayItem overlayitem = new OverlayItem(point,"","" );
              itemizedoverlay.addOverlay(overlayitem);
              mapOverlays.add(itemizedoverlay);

}
        } */


    @Override
    protected boolean isRouteDisplayed() {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public void onLocationChanged(Location location) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onProviderDisabled(String provider) {

Toast.makeText(getBaseContext(),"GPS Disabled",Toast.LENGTH_SHORT).show();      

    }

    @Override
    public void onProviderEnabled(String provider) {

        Toast.makeText(getBaseContext(),"GPS Enabled",Toast.LENGTH_SHORT).show();

    }

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

    }

你能为我建议一个解决方案吗？在此先感谢，如果我在这里犯了任何错误，我很抱歉。

Answer 1

试试这个 -

/**
* Setting Google Map to provided location 
*/
 private void setMaptoLocation(Location location) {
  mapView.setBuiltInZoomControls(true);
  mapView.setSatellite(true);
  int LAT = (int)(location.getLatitude() * 1E6) ;
  int LNG = (int)(location.getLongitude() * 1E6) ;
  GeoPoint point = new GeoPoint(LAT, LNG);
  mapController = mapView.getController();
  List<Overlay> mapOverlays = mapView.getOverlays();
  Drawable drawable = this.getResources().getDrawable(R.drawable.icon);
  HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(drawable,this);
  OverlayItem overlayitem = new OverlayItem(point,"","" );
  itemizedoverlay.addOverlay(overlayitem);
  mapOverlays.add(itemizedoverlay);
  mapController.setZoom(ZOOM_LEVEL - ZOOM_LEVEL / 2); // Set zoom level per requierment
  mapController.animateTo(point);

 }

Answer 2

您可以使用com.google.android.maps.MyLocationOverlay，它会自动在地图视图中显示您的位置。它甚至会在旅行时更新您的位置。

注意：分别在onResume和onPause上显示调用enableMyLocation和disableMyLocation以获得更好的性能。

@Override
    protected void onResume() {
        super.onResume();
        if (locationOverlay != null)
            locationOverlay.enableMyLocation();
    }

    @Override
    protected void onPause() {
        if (locationOverlay != null)
            locationOverlay.disableMyLocation();
        super.onPause();
    }

<强> EDITED

MyLocationOverlay locationOverlay;

public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
      setContentView(R.layout.main);

      mapView = (MapView) findViewById(R.id.mapView);
      mapView.setTraffic(true);
      mapView.setBuiltInZoomControls(true);
locationOverlay = new MyLocationOverlay(this, mapView);
List<Overlay> mapOverlays = mapView.getOverlays();
 mapOverlays.add(locationOverlay);
}

还添加onResume（）和onPause（）方法。

Answer 3

我认为你必须使用Google Maps Android API v2

有关详细信息，请查看Google Maps Android API v2。

请检查上述链接中示例代码的链接。 sample code

Answer 4

你在 onCreate（）中初始化

位置是没有的，所以我猜它是空的。还有一件事，如果你有Lat和Long，逐项列出肯定会在地图上显示位置。在Manifest中检查权限 Access_Course_location 和 Access_fine_location 。

当前位置不是在Android中挑选

4 个答案: