如何在android中的地图上显示当前位置标记？

How to show current position marker on Map in android?

提问by Durga

I am developing an application in which I want to display current location using marker in my map. I am using Google Map v2. Here I can display Map and marker when GPS is off ,but not visible any marker on map when GPS on. My requirement is display marker on map with current position

我正在开发一个应用程序，我想在其中使用地图中的标记显示当前位置。我正在使用谷歌地图 v2。在这里，我可以在 GPS 关闭时显示地图和标记，但在 GPS 开启时在地图上看不到任何标记。我的要求是在地图上显示当前位置的标记

I tried like this,

我是这样试的

@Override
public void onLocationChanged(Location location) {
    // TODO Auto-generated method stub

    //locationManger.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0,        
               this);

    ArrayList<HashMap<String, String>> arl = (ArrayList<HashMap<String, String>>) 
            getIntent().getSerializableExtra("arrayList");


    if(location!=null){
        double latitude = location.getLatitude();
        double langitude = location.getLongitude();


        myPosition = new LatLng(latitude, langitude);
        CameraPosition position= new  CameraPosition.Builder().
              target(myPosition).zoom(17).bearing(19).tilt(30).build();
        //_googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(position));

        _googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(position)); 
        _googleMap.addMarker(new   
                  MarkerOptions().position(myPosition).title("start"));
    }

回答by jyomin

Use below code it worked for me:

使用以下代码对我有用：

 @Override
 public void onLocationChanged(Location location) {

   map.clear();

   MarkerOptions mp = new MarkerOptions();

   mp.position(new LatLng(location.getLatitude(), location.getLongitude()));

   mp.title("my position");

   map.addMarker(mp);

   map.animateCamera(CameraUpdateFactory.newLatLngZoom(
    new LatLng(location.getLatitude(), location.getLongitude()), 16));

  }

回答by poojagupta

Try this,it is showing current location:

试试这个，它显示当前位置：

private void initilizeMap() {
    if (googleMap == null) {
        googleMap = ((MapFragment) getFragmentManager().findFragmentById(
                R.id.map)).getMap();
                // to set current location
        googleMap.setMyLocationEnabled(true);

        // check if map is created successfully or not
        if (googleMap == null) {
            Toast.makeText(getApplicationContext(),
                    "Sorry! unable to create maps", Toast.LENGTH_SHORT)
                    .show();
        }
    }

回答by Sai Aditya

Use this. It works for me.

用这个。这个对我有用。

@Override
public void onLocationChanged(Location location) {
    map.clear();

    mp1 = new MarkerOptions();
    mp1.position(new LatLng(location.getLatitude(),
            location.getLongitude()));

    mp1.draggable(true);
    mp1.icon(BitmapDescriptorFactory
            .defaultMarker(BitmapDescriptorFactory.HUE_ROSE));
    map.addMarker(mp1);

    map.animateCamera(CameraUpdateFactory.newLatLngZoom(
            new LatLng(location.getLatitude(), location
                    .getLongitude()), 20));
}

回答by demo demo

You may try this:

你可以试试这个：

public class MapsActivity extends AppCompatActivity
        implements OnMapReadyCallback,
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener,
        LocationListener {

    GoogleMap mGoogleMap;
    SupportMapFragment mapFrag;
    LocationRequest mLocationRequest;
    GoogleApiClient mGoogleApiClient;
    Location mLastLocation;
    Marker mCurrLocationMarker;
    private Circle mCircle;

    double radiusInMeters = 100.0;
    int strokeColor = 0xffff0000; //Color Code you want
    int shadeColor = 0x44ff0000; //opaque red fill

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

        getSupportActionBar().setTitle("Map Location Activity");

        mapFrag = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
        mapFrag.getMapAsync(this);
    }

    @Override
    public void onPause() {
        super.onPause();

        //stop location updates when Activity is no longer active
        if (mGoogleApiClient != null) {
            LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
        }
    }

    @Override
    public void onMapReady(GoogleMap googleMap)
    {
        mGoogleMap=googleMap;
        //mGoogleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);

        //Initialize Google Play Services
        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (ContextCompat.checkSelfPermission(this,
                    Manifest.permission.ACCESS_FINE_LOCATION)
                    == PackageManager.PERMISSION_GRANTED) {
                //Location Permission already granted
                buildGoogleApiClient();
                mGoogleMap.setMyLocationEnabled(true);
            } else {
                //Request Location Permission
                checkLocationPermission();
            }
        }
        else {
            buildGoogleApiClient();
            mGoogleMap.setMyLocationEnabled(true);
        }
    }

    protected synchronized void buildGoogleApiClient() {
        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
        mGoogleApiClient.connect();
    }

    @Override
    public void onConnected(Bundle bundle) {
        mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(1000);
        mLocationRequest.setFastestInterval(1000);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
            LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
        }
    }

    @Override
    public void onConnectionSuspended(int i) {}

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {}

    @Override
    public void onLocationChanged(Location location)
    {
        mLastLocation = 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_MAGENTA));
        mCurrLocationMarker = mGoogleMap.addMarker(markerOptions);

        CircleOptions addCircle = new CircleOptions().center(latLng).radius(radiusInMeters).fillColor(shadeColor).strokeColor(strokeColor).strokeWidth(8);
        mCircle = mGoogleMap.addCircle(addCircle);

        //move map camera
        mGoogleMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
        mGoogleMap.animateCamera(CameraUpdateFactory.zoomTo(11));

        //stop location updates
        if (mGoogleApiClient != null) {
            LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
        }
    }

    public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99;
    private void checkLocationPermission() {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {

            // Should we show an explanation?
            if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                    Manifest.permission.ACCESS_FINE_LOCATION)) {

                // Show an explanation to the user *asynchronously* -- don't block
                // this thread waiting for the user's response! After the user
                // sees the explanation, try again to request the permission.
                new AlertDialog.Builder(this)
                        .setTitle("Location Permission Needed")
                        .setMessage("This app needs the Location permission, please accept to use location functionality")
                        .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialogInterface, int i) {
                                //Prompt the user once explanation has been shown
                                ActivityCompat.requestPermissions(MapsActivity.this,
                                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                                        MY_PERMISSIONS_REQUEST_LOCATION );
                            }
                        })
                        .create()
                        .show();


            } else {
                // No explanation needed, we can request the permission.
                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                        MY_PERMISSIONS_REQUEST_LOCATION );
            }
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           String permissions[], int[] grantResults) {
        switch (requestCode) {
            case MY_PERMISSIONS_REQUEST_LOCATION: {
                // If request is cancelled, the result arrays are empty.
                if (grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    // permission was granted, yay! Do the
                    // location-related task you need to do.
                    if (ContextCompat.checkSelfPermission(this,
                            Manifest.permission.ACCESS_FINE_LOCATION)
                            == PackageManager.PERMISSION_GRANTED) {

                        if (mGoogleApiClient == null) {
                            buildGoogleApiClient();
                        }
                        mGoogleMap.setMyLocationEnabled(true);
                    }

                } else {

                    // permission denied, boo! Disable the
                    // functionality that depends on this permission.
                    Toast.makeText(this, "permission denied", Toast.LENGTH_LONG).show();
                }
                return;
            }

            // other 'case' lines to check for other
            // permissions this app might request
        }
    }

回答by Namrata

Try this:-

尝试这个：-

private void initMap() {
    if (googleMap != null) {
        googleMap = ((MapFragment) getFragmentManager().findFragmentById(
                R.id.map)).getMap();
                // to set current location
        googleMap.setMyLocationEnabled(true);
        Marker pos_Marker =  googleMap.addMarker(new MarkerOptions().position(starting).icon(BitmapDescriptorFactory.fromResource(R.drawable.ic_laumcher)).title("Starting Location").draggable(false));

        pos_Marker.showInfoWindow();
        googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(START_locationpoint, 10));
        googleMap.animateCamera(CameraUpdateFactory.zoomTo(15),2000, null);  

        // check if map is created successfully or not
        if (googleMap == null) {
            Toast.makeText(getApplicationContext(),
                    "Sorry! unable to create maps", Toast.LENGTH_SHORT)
                    .show();
        }
    }

回答by Shahzad Afridi

  Location mlocation;

    @Override 
    public void onLocationChanged(Location location) { 
        // Add a marker in Sydney and move the camera 
        mLocation = location; 
        LatLng myLocation = new LatLng(mLocation.getLatitude(), mLocation.getLongitude());
        mMap.addMarker(new MarkerOptions()
                .position(myLocation)
                .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED))
                .title("My Location"));
        mMap.moveCamera(CameraUpdateFactory.newLatLng(myLocation));
        Log.d("location", "Latitude:" + mLocation.getLatitude() + "\n" + "Longitude:" + mLocation.getLongitude());
    } 

回答by Ali Faradjpour

for getting current position you can use getLastKnownLocation() method on LocationManager:

要获取当前位置，您可以在 LocationManager 上使用 getLastKnownLocation() 方法：

locationManager = (LocationManager) getActivity().getSystemService(getActivity().LOCATION_SERVICE);                    
Location currentLocation = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

LatLng current = new LatLng(currentLocation.getLatitude(), currentLocation.getLongitude());
googleMap.addMarker(new MarkerOptions().position(current).title("Marker Label").snippet("Marker Description"));

CameraPosition cameraPosition = new CameraPosition.Builder().target(current).zoom(14).build();
googleMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));

回答by Rohit Bhandari

mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
        @Override
        public void onMapClick(LatLng latLng) {
            float lat = (float) latLng.latitude;
            float lon = (float) latLng.longitude;
            mMap.clear();
            mMap.addMarker(new MarkerOptions().position(latLng).title("Marker in " + lat +" "+ lon));
            mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));

        }
    });