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如何在安卓地图上显示当前位置标记？

androidgoogle-mapsgoogle-maps-markers
6

我正在开发一个应用程序，我想在我的地图中使用标记来显示当前位置。我正在使用 Google Map v2。当GPS关闭时，我可以显示地图和标记，但是当GPS打开时，地图上没有任何标记可见。我的要求是在地图上显示具有当前位置的标记。

我尝试了以下方法：

@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"));
    }
8个回答
8

使用以下代码可以解决问题：

 @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));

  }
对我来说不起作用。实际上问题是它在2.3设备上可以运行，但在4.2设备上无法运行。 - Durga
3

使用这个。它对我来说很有效。

@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));
}
3

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();
        }
    }
对我来说不起作用。实际问题是它在2.3设备上可以工作，但在4.2设备上无法工作。 - Durga
对不起，我发现了这个问题。如果GPS打开，则标记不会显示，但是如果GPS关闭，则标记会显示。为什么？请告诉我。 - Durga
3

尝试这个，它会显示当前位置：

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();
        }
    }
2
您可以尝试这个方法：
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
        }
    }
0
获取当前位置时，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));
0
  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());
    }
-2
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));

        }
    });
这个答案在SO的低质量帖子中出现，因为它只是一个代码答案。你能否请添加一些解释到你的答案中？解释你的逻辑，并对你的代码意图进行一些评论。这不仅有助于OP，而且还将作为未来用户的评论。来自审查。 - dbc
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