问题
I\'m trying to mess around with the Maps API V2 to get more familiar with it, and I\'m trying to start the map centered at the user\'s current location. Using the map.setMyLocationEnabled(true); statement, I am able to show my current location on the map. This also adds the button to the UI that centers the map on my current location.
I want to simulate that button press in my code. I am familiar with the LocationManager and LocationListener classes and realize that using those is a viable alternative, but the functionality to center and zoom in on the user\'s location seems to already be built in through the button.
If the API has a method to show the user\'s current location, there surely must be an easier way to center on the location than to use the LocationManager/LocationListener classes, right?
回答1:
Try this coding:
LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
Location location = locationManager.getLastKnownLocation(locationManager.getBestProvider(criteria, false));
if (location != null)
{
map.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(location.getLatitude(), location.getLongitude()), 13));
CameraPosition cameraPosition = new CameraPosition.Builder()
.target(new LatLng(location.getLatitude(), location.getLongitude())) // Sets the center of the map to location user
.zoom(17) // Sets the zoom
.bearing(90) // Sets the orientation of the camera to east
.tilt(40) // Sets the tilt of the camera to 30 degrees
.build(); // Creates a CameraPosition from the builder
map.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}
回答2:
After you instansiated the map object (from the fragment) add this -
private void centerMapOnMyLocation() {
map.setMyLocationEnabled(true);
location = map.getMyLocation();
if (location != null) {
myLocation = new LatLng(location.getLatitude(),
location.getLongitude());
}
map.animateCamera(CameraUpdateFactory.newLatLngZoom(myLocation,
Constants.MAP_ZOOM));
}
if you need any guidance just ask but it should be self explantory - just instansiate the myLocation object for a default one...
回答3:
youmap.animateCamera(CameraUpdateFactory.newLatLngZoom(currentlocation, 16));
16 is the zoom level
回答4:
mMap.setOnMyLocationChangeListener(new GoogleMap.OnMyLocationChangeListener() {
@Override
public void onMyLocationChange(Location location) {
CameraUpdate center=CameraUpdateFactory.newLatLng(new LatLng(location.getLatitude(), location.getLongitude()));
CameraUpdate zoom=CameraUpdateFactory.zoomTo(11);
mMap.moveCamera(center);
mMap.animateCamera(zoom);
}
});
回答5:
try this code :
private GoogleMap mMap;
LocationManager locationManager;
private static final String TAG = "";
@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(map);
mapFragment.getMapAsync(this);
arrayPoints = new ArrayList<LatLng>();
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
LatLng myPosition;
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;
}
googleMap.setMyLocationEnabled(true);
LocationManager locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria criteria = new Criteria();
String provider = locationManager.getBestProvider(criteria, true);
Location location = locationManager.getLastKnownLocation(provider);
if (location != null) {
double latitude = location.getLatitude();
double longitude = location.getLongitude();
LatLng latLng = new LatLng(latitude, longitude);
myPosition = new LatLng(latitude, longitude);
LatLng coordinate = new LatLng(latitude, longitude);
CameraUpdate yourLocation = CameraUpdateFactory.newLatLngZoom(coordinate, 19);
mMap.animateCamera(yourLocation);
}
}
}
Dont forget to add permissions on AndroidManifest.xml.
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
回答6:
private void setUpMapIfNeeded(){
if (mMap == null){
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();//invoke of map fragment by id from main xml file
if (mMap != null) {
mMap.setMyLocationEnabled(true);//Makes the users current location visible by displaying a blue dot.
LocationManager lm=(LocationManager)getSystemService(LOCATION_SERVICE);//use of location services by firstly defining location manager.
String provider=lm.getBestProvider(new Criteria(), true);
if(provider==null){
onProviderDisabled(provider);
}
Location loc=lm.getLastKnownLocation(provider);
if (loc!=null){
onLocationChanged(loc);
}
}
}
}
// Initialize map options. For example:
// mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
@Override
public void onLocationChanged(Location location) {
LatLng latlng=new LatLng(location.getLatitude(),location.getLongitude());// This methods gets the users current longitude and latitude.
mMap.moveCamera(CameraUpdateFactory.newLatLng(latlng));//Moves the camera to users current longitude and latitude
mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(latlng,(float) 14.6));//Animates camera and zooms to preferred state on the user's current location.
}
// TODO Auto-generated method stub
回答7:
Here's how to do it inside ViewModel and FusedLocationProviderClient, code in Kotlin
locationClient.lastLocation.addOnSuccessListener { location: Location? ->
location?.let {
val position = CameraPosition.Builder()
.target(LatLng(it.latitude, it.longitude))
.zoom(15.0f)
.build()
map.animateCamera(CameraUpdateFactory.newCameraPosition(position))
}
}
回答8:
This is working Current Location with zoom for Google Map V2
double lat= location.getLatitude();
double lng = location.getLongitude();
LatLng ll = new LatLng(lat, lng);
googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(ll, 20));
回答9:
check this out:
fun requestMyGpsLocation(context: Context, callback: (location: Location) -> Unit) {
val request = LocationRequest()
// request.interval = 10000
// request.fastestInterval = 5000
request.numUpdates = 1
request.priority = LocationRequest.PRIORITY_HIGH_ACCURACY
val client = LocationServices.getFusedLocationProviderClient(context)
val permission = ContextCompat.checkSelfPermission(context,
Manifest.permission.ACCESS_FINE_LOCATION )
if (permission == PackageManager.PERMISSION_GRANTED) {
client.requestLocationUpdates(request, object : LocationCallback() {
override fun onLocationResult(locationResult: LocationResult?) {
val location = locationResult?.lastLocation
if (location != null)
callback.invoke(location)
}
}, null)
}
}
and
fun zoomOnMe() {
requestMyGpsLocation(this) { location ->
mMap?.animateCamera(CameraUpdateFactory.newLatLngZoom(
LatLng(location.latitude,location.longitude ), 13F ))
}
}
来源：https://stackoverflow.com/questions/18425141/android-google-maps-api-v2-zoom-to-current-location