Question

我想在Android应用中显示当前用户位置，例如GMaps中的蓝点。我在网上搜索，但我可能遗漏了一些重要的东西。

这些是我的类派生的类或接口

public class TargetActivity : AppCompatActivity, IOnMapReadyCallback, Android.Locations.ILocationListener

这段代码来自我的MainActivity，这是我第一次在Android上编程，所以我真的不知道从哪里开始。

    public GoogleMap _map;
    public MapFragment _mapFragment;
    LocationManager locationManager;
    string provider;

    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.Target);

        _mapFragment = FragmentManager.FindFragmentById(Resource.Id.map) as MapFragment;
        if (_mapFragment == null)
        {
            GoogleMapOptions mapOptions = new GoogleMapOptions()
                .InvokeMapType(GoogleMap.MapTypeTerrain)
                .InvokeZoomControlsEnabled(false)
                .InvokeCompassEnabled(true);

            FragmentTransaction fragTx = FragmentManager.BeginTransaction();
            _mapFragment = MapFragment.NewInstance(mapOptions);
            fragTx.Add(Resource.Id.map, _mapFragment, "map");
            fragTx.Commit();


        }
        _mapFragment.GetMapAsync(this);

        if (_map != null)
        {
            _map.UiSettings.ZoomControlsEnabled = false; 
            _map.UiSettings.CompassEnabled = true;  
            _map.MapType = GoogleMap.MapTypeTerrain;   

        }

        locationManager = (LocationManager)GetSystemService(Context.LocationService);
        provider = locationManager.GetBestProvider(new Criteria(), false);

        Location location = locationManager.GetLastKnownLocation(provider);
        if (location == null)
        {
            System.Diagnostics.Debug.WriteLine("no location");
        }
    }

    public void OnMapReady(GoogleMap googleMap)
    {
        MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.SetPosition(new LatLng(16.03, 108));
        markerOptions.SetTitle("AAAA");
        googleMap.AddMarker(markerOptions);
    }

    public void OnLocationChanged(Location location)
    {

        double lat, lng;
        lat = location.Latitude;
        lng = location.Longitude;

        MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.SetPosition(new LatLng(lat, lng));
        markerOptions.SetTitle("Posizione");
        _map.AddMarker(markerOptions);

        CameraPosition.Builder builder = CameraPosition.InvokeBuilder();
        builder.Target(new LatLng(lat, lng));
        CameraPosition cameraPosition = builder.Build();
        CameraUpdate cameraUpdate = CameraUpdateFactory.NewCameraPosition(cameraPosition);
        _map.MoveCamera(cameraUpdate);

    }

public void OnProviderDisabled(string provider)
        {
            //throw new NotImplementedException();

        }

        public void OnProviderEnabled(string provider)
        {
            //throw new NotImplementedException();
        }

        public void OnStatusChanged(string provider, [GeneratedEnum] Availability status, Bundle extras)
        {
            //throw new NotImplementedException();
        }

Answer 1

您需要实施OnMyLocationButtonClickListener和OnMyLocationClickListener。在地图实例上启用位置服务并覆盖相关方法。只要您拥有定位权限，几乎所有内容都会为您完成。请查看文档here

通过Google Play服务获取Xamarin中的用户位置

1 个答案: