Android：如何使用谷歌地图在我的应用中显示用户当前位置？

Question

如何使用谷歌地图在我的应用中显示用户当前位置？我想使用移动网络或 GPS（如果可用）向用户显示当前位置。我没有找到任何可以帮助我的教程，或者它们太难理解了。

这是我的 Map.java 活动的代码，你能给我我需要的代码吗？谢谢！

import java.util.List;

public class Map extends MapActivity
{

 @Override
 public void onCreate(Bundle savedInstanceState)
 {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.map);

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

 MapController mc = mapView.getController();
 String coordinates[] = {"54.6738310", "025.2740480"};
 double lat = Double.parseDouble(coordinates[0]);
 double lng = Double.parseDouble(coordinates[1]);

 GeoPoint p = new GeoPoint(
     (int) (lat * 1E6), 
     (int) (lng * 1E6));

 mc.animateTo(p);
 mc.setZoom(13); 
 mapView.invalidate();

 List<Overlay> mapOverlays = mapView.getOverlays();
 Drawable drawable = this.getResources().getDrawable(R.drawable.icon);
 HelloItemizedOverlay itemizedoverlay = new HelloItemizedOverlay(drawable,this);
 GeoPoint point = new GeoPoint(30443769,-91158458);
 OverlayItem overlayitem = new OverlayItem(point, "Laissez les bon temps rouler!", "I'm in Louisiana!");

 GeoPoint point2 = new GeoPoint(17385812,78480667);
 OverlayItem overlayitem2 = new OverlayItem(point2, "Namashkaar!", "I'm in Hyderabad, India!");

 itemizedoverlay.addOverlay(overlayitem);
 itemizedoverlay.addOverlay(overlayitem2);

 mapOverlays.add(itemizedoverlay);
 }


 @Override
 protected boolean isRouteDisplayed()
 {
 return false;
 }
}

Answer 1

您需要将地图视图与位置管理器结合使用。多亏了这一点，您可以获取用户位置并将其绘制在地图中（作为另一个叠加层）。看看这个link，这是一个获取职位的教程。

Answer 2

    public class MainActivity extends FragmentActivity implements OnMapReadyCallback,
    GoogleApiClient.ConnectionCallbacks,
    GoogleApiClient.OnConnectionFailedListener,
    GoogleMap.OnMarkerDragListener,
    GoogleMap.OnMapLongClickListener,
    GoogleMap.OnMarkerClickListener, LocationListener,
    View.OnClickListener {


private static final String TAG = "MapsActivity";
private GoogleMap mMap;
private GoogleApiClient googleApiClient;

private Marker mCurrLocationMarker;
private LocationRequest mLocationRequest;
private ArrayList<LatLng> routePoints;
private Polyline line;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // 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);


    //Initializing googleApiClient
    googleApiClient = new GoogleApiClient.Builder(this)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(LocationServices.API)
            .build();

    routePoints = new ArrayList<LatLng>();
}

@Override
public void onClick(View v) {

}

@Override
public void onConnected(Bundle bundle) {
    mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(1000);
    mLocationRequest.setFastestInterval(1000);
    mLocationRequest.setSmallestDisplacement(0.1F); //added
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY); //changed
    if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.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;
    }
    LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient, mLocationRequest, this);
}




  @Override
public void onMapReady(GoogleMap googleMap) {
    mMap = googleMap;
    mMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
    // googleMapOptions.mapType(googleMap.MAP_TYPE_HYBRID)
    //    .compassEnabled(true);

    // Add a marker in Sydney and move the camera
    LatLng india = new LatLng(20.5937, 78.9629);
    mMap.addMarker(new MarkerOptions().position(india).title("Marker in India"));
    mMap.moveCamera(CameraUpdateFactory.newLatLng(india));
    mMap.setOnMarkerDragListener(this);
    mMap.setOnMapLongClickListener(this);
}


@Override
protected void onStart() {
    googleApiClient.connect();
    super.onStart();
}

@Override
protected void onStop() {
    googleApiClient.disconnect();
    super.onStop();
}

@Override
public void onLocationChanged(Location location) {

    if (mCurrLocationMarker != null) {
        mCurrLocationMarker.remove();
    }


    //Place current location marker
    LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude());
    MarkerOptions markerOptions = new MarkerOptions();
    markerOptions.position(latLng);
    markerOptions.title("Current Position");
    markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
    mCurrLocationMarker = mMap.addMarker(markerOptions);

    //move map camera
    mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
    mMap.animateCamera(CameraUpdateFactory.zoomTo(18));

    PolylineOptions pOptions = new PolylineOptions()
            .width(5)
            .color(Color.GREEN)
            .geodesic(true);
    for (int z = 0; z < routePoints.size(); z++) {
        LatLng point = routePoints.get(z);
        pOptions.add(point);
    }
    line = mMap.addPolyline(pOptions);
    routePoints.add(latLng);
}
}