How to mark my current location on google map?
I am using google place API. I have to show all near places from my current position. All places are showing on google map, but how to show my current position? The code is given below:
public class PoliceStationMapActivity extends FragmentActivity implements LocationListener {
private ArrayList<Place> mArrayListPoliceStations;
private GoogleMap mMap;
private LocationManager locManager;
private double latitude;
private double longitude;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_police_station);
locManager = (LocationManager) getSystemService(LOCATION_SERVICE);
if (locManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER))
locManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this);
else
Log.i("Test", "network provider unavailable");
Location lastKnownLocation = locManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
latitude = lastKnownLocation.getLatitude();
longitude = lastKnownLocation.getLongitude();
if (lastKnownLocation != null) {
Log.i("Test", lastKnownLocation.getLatitude() + ", " + lastKnownLocation.getLongitude());
locManager.removeUpdates(this);
}
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
if (mMap != null) {
new GetAllPoliceStationsTask().execute("" + latitude, "" + longitude);
}
}
private class GetAllPoliceStationsTask extends AsyncTask<String, Void, ArrayList<Place>> {
@Override
protected ArrayList<Place> doInBackground(String... param) {
ArrayList<Place> policeStationsList = RequestHandler.getInstance(PoliceStationMapActivity.this).getAllPlaces(param[0], param[1]);
return policeStationsList;
}
@Override
protected void onPostExecute(java.util.ArrayList<Place> result) {
if (result != null) {
mArrayListPoliceStations = result;
placeAllPoliceStationMarkersOnMap(mArrayListPoliceStations);
}
}
}
private void placeAllPoliceStationMarkersOnMap(ArrayList<Place> policeStationList) {
for (Place place : policeStationList) {
addPlaceMarkerOnMap(place);
}
};
private void addPlaceMarkerOnMap(Place place) {
LatLng latLng = new LatLng(place.getLatitude(), place.getLongitude());
Marker poiMarker = mMap.addMarker(new MarkerOptions().position(latLng).title(place.getName()).snippet(place.getVicinity()));
Marker currentMarker = mMap.addMarker(new MarkerOptions().position());
}
@Override
public void onLocationChanged(Location location) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}`
First, to obtain the current location:
private Location mCurrentLocation;
mCurrentLocation = mLocationClient.getLastLocation();
Read here to know more.
And then you can point to the location using:
LatLng myLaLn = new LatLng(mCurrentLocation.getLatitude(), mCurrentLocation.getLongitude());
CameraPosition camPos = new CameraPosition.Builder().target(myLaLn)
.zoom(15)
.bearing(45)
.tilt(70)
.build();
CameraUpdate camUpd3 = CameraUpdateFactory.newCameraPosition(camPos);
map.animateCamera(camUpd3);
I give you a simple but complete example to show a map and the current location:
(Full project available in github.com/josuadas/LocationDemo )
public class MainActivity extends FragmentActivity implements
GooglePlayServicesClient.ConnectionCallbacks,
GooglePlayServicesClient.OnConnectionFailedListener {
private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000;
private LocationClient mLocationClient;
private Location mCurrentLocation;
private GoogleMap map;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
setUpLocationClientIfNeeded();
mLocationClient.connect();
}
private void setUpMapIfNeeded() {
// Do a null check to confirm that we have not already instantiated the
// map.
if (map == null) {
// Try to obtain the map from the SupportMapFragment.
map = ((SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map)).getMap();
// Check if we were successful in obtaining the map.
if (map == null) {
Toast.makeText(this, "Google maps not available",
Toast.LENGTH_LONG).show();
}
}
}
private void setUpLocationClientIfNeeded() {
if (mLocationClient == null) {
Toast.makeText(getApplicationContext(), "Waiting for location",
Toast.LENGTH_SHORT).show();
mLocationClient = new LocationClient(getApplicationContext(), this, // ConnectionCallbacks
this); // OnConnectionFailedListener
}
}
@Override
public void onPause() {
super.onPause();
if (mLocationClient != null) {
mLocationClient.disconnect();
}
}
/*
* Called by Location Services when the request to connect the client
* finishes successfully. At this point, you can request the current
* location or start periodic updates
*/
@Override
public void onConnected(Bundle dataBundle) {
mCurrentLocation = mLocationClient.getLastLocation();
if (mCurrentLocation != null) {
Toast.makeText(getApplicationContext(), "Found!",
Toast.LENGTH_SHORT).show();
centerInLoc();
}
}
private void centerInLoc() {
LatLng myLaLn = new LatLng(mCurrentLocation.getLatitude(),
mCurrentLocation.getLongitude());
CameraPosition camPos = new CameraPosition.Builder().target(myLaLn)
.zoom(15).bearing(45).tilt(70).build();
CameraUpdate camUpd3 = CameraUpdateFactory.newCameraPosition(camPos);
map.animateCamera(camUpd3);
MarkerOptions markerOpts = new MarkerOptions().position(myLaLn).title(
"my Location");
map.addMarker(markerOpts);
}
/*
* Called by Location Services if the connection to the location client
* drops because of an error.
*/
@Override
public void onDisconnected() {
// Display the connection status
Toast.makeText(this, "Disconnected. Please re-connect.",
Toast.LENGTH_SHORT).show();
}
/*
* Called by Location Services if the attempt to Location Services fails.
*/
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
/*
* Google Play services can resolve some errors it detects. If the error
* has a resolution, try sending an Intent to start a Google Play
* services activity that can resolve error.
*/
if (connectionResult.hasResolution()) {
try {
// Start an Activity that tries to resolve the error
connectionResult.startResolutionForResult(this,
CONNECTION_FAILURE_RESOLUTION_REQUEST);
/*
* Thrown if Google Play services canceled the original
* PendingIntent
*/
} catch (IntentSender.SendIntentException e) {
// Log the error
e.printStackTrace();
}
} else {
/*
* If no resolution is available
*/
Log.e("Home", Integer.toString(connectionResult.getErrorCode()));
}
}
}
Note1: I omitted the "Check for Google Play Services" part by simplicity but it should be added as a good practice.
Note2: You need the google-play-services_lib project and reference it from yours.
You can find all information about interacting with google maps in android here
See followed snippets of code:
...
MyLocationOverlay myLoc = null;
MapView myMapView = null;
GeoPoint mCurrentPoint;
...
myMapView = (MapView) findViewById(R.id.mapView);
myMapView.setBuiltInZoomControls(true);
myMapView.setStreetView(true);
mc = myMapView.getController();
mc.setZoom(17);
myLoc = new CustomMyLocationOverlay(this, myMapView);
myLoc.runOnFirstFix(new Runnable() {
public void run() {
if (mCurrentPoint.equals(new GeoPoint(0,0))){
mc.animateTo(myLoc.getMyLocation());
mCurrentPoint = myLoc.getMyLocation();
}
}
});
myMapView.getOverlays().add(myLoc);
myMapView.postInvalidate();
zoomToMyLocation();
Drawable drawable = this.getResources().getDrawable(R.drawable.target);
mItemizedoverlay = new MyItemizedOverlay(drawable, this);
// here get your lat, longt as double and put in GeoPoint
mCurrentPoint = new GeoPoint((int)lat,(int)lon);
if (!mCurrentPoint.equals(new GeoPoint(0,0))){
mc.animateTo(mCurrentPoint);
setMarker();
}
...
public void zoomToMyLocation() {
mCurrentPoint = myLoc.getMyLocation();
if (mCurrentPoint != null) {
myMapView.getController().animateTo(mCurrentPoint);
// myMapView.getController().setZoom(10);
}
}
map.xml
<com.google.android.maps.MapView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/mapView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:clickable="true"
android:enabled="true"
android:apiKey="xxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
/>
Hope it will help you
mMap.setMyLocationEnabled(true);
This line will show an icon at top right corner of the map, after clicking on which it takes to your current location on map.
来源：https://stackoverflow.com/questions/18546234/mark-current-location-on-google-map