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);
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) {
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