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如何在谷歌地图、Android Studio中删除新位置的旧位置标记?

  •  0
  • husen  · 技术社区  · 7 年前

    此代码可用,但我对标记有问题,当我运行应用程序时,它确实会显示标记,但当我步行更改位置时,旧的位置标记仍会显示在应用程序上,并且我的最新位置也会显示,我如何删除旧的位置标记?

    这是我的活动。Java语言

    package stmikbumigoramataram.intro;
    
    import android.Manifest;
    import android.content.pm.PackageManager;
    import android.location.Address;
    import android.location.Geocoder;
    import android.location.Location;
    import android.location.LocationListener;
    import android.location.LocationManager;
    import android.support.v4.app.ActivityCompat;
    import android.support.v4.app.FragmentActivity;
    import android.os.Bundle;
    import android.util.Log;
    
    import com.google.android.gms.maps.CameraUpdateFactory;
    import com.google.android.gms.maps.GoogleMap;
    import com.google.android.gms.maps.OnMapReadyCallback;
    import com.google.android.gms.maps.SupportMapFragment;
    import com.google.android.gms.maps.model.CameraPosition;
    import com.google.android.gms.maps.model.LatLng;
    import com.google.android.gms.maps.model.Marker;
    import com.google.android.gms.maps.model.MarkerOptions;
    
    import java.io.IOException;
    import java.util.List;
    
    public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
    
    private GoogleMap mMap;
    private LocationManager locationManager;
    private LocationListener locationListener;
    Marker currLocationMarker;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    
        locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
    
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
    
        locationListener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                double latitude = location.getLatitude();
                double longitude = location.getLongitude();
    
               if(currLocationMarker != null){
                   currLocationMarker.remove();
               }
    
                LatLng latLng = new LatLng(latitude, longitude);
                Geocoder geocoder = new Geocoder(getApplicationContext());
                try {
                    List<Address> addressList = geocoder.getFromLocation(latitude, longitude, 1);
                    String str = addressList.get(0).getLocality()+", ";
                    str += addressList.get(0).getCountryName();
                    currLocationMarker = mMap.addMarker(new MarkerOptions().position(latLng).title(str));
    
                } catch (IOException e) {
                    e.printStackTrace();
                }
                CameraPosition cameraPosition = new CameraPosition.Builder().target(new LatLng(latLng.latitude, latLng.longitude)).zoom(15).build();
                mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
            }
    
            @Override
            public void onStatusChanged(String provider, int status, Bundle extras) {
    
            }
    
            @Override
            public void onProviderEnabled(String provider) {
    
            }
    
            @Override
            public void onProviderDisabled(String provider) {
    
            }
        };
    
    
        locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
    }
    
    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
    
    }
    
    protected void onPause() {
        super.onPause();
        locationManager.removeUpdates(locationListener);
        Log.i("onPause...","paused");
    }
    }
    

    You can see result of my code here

    1 回复  |  直到 7 年前
        1
  •  2
  •   Pang Ajmal PraveeN    7 年前

    您应该首先清除Google地图,然后添加一个新标记,该标记显示为“上一个标记删除”和“新标记添加”。

    使用此行:

    googleMap.clear();
    

    在谷歌地图上添加新标记后。