How to Add Snap to Roads Google Map in Android Studio

问题:

Hello I would like to ask how to add Snap to Road when I have the route given by google map API. I have a bunch of Lat lang from point A line to point B line and draw a lines like Polylines, but what i want is how to add this code snap to Road from given route? this is how to add more points from the Point A to Point B, here is what i want to add, https://developers.google.com/maps/documentation/roads/snap

my project is look like this

回答1:

1. Get overview_polyline by Json and Gson (should use https://maps.googleapis.com/maps/api/directions/json?origin=...&destination=place_id:...&mode=DRIVING&key=...)

2. Decode it to List by function

   public List<LatLng> decodePoly(String encoded) { // encoded is overview_polyline.points;  List<LatLng> poly = new ArrayList<LatLng>(); int index = 0, len = encoded.length(); int lat = 0, lng = 0; while (index < len) {     int b, shift = 0, result = 0;     do {         b = encoded.charAt(index++) - 63;         result |= (b & 0x1f) << shift;         shift += 5;     } while (b >= 0x20);     int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));     lat += dlat;      shift = 0;     result = 0;     do {         b = encoded.charAt(index++) - 63;         result |= (b & 0x1f) << shift;         shift += 5;     } while (b >= 0x20);     int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));     lng += dlng;      LatLng p = new LatLng((((double) lat / 1E5)),             (((double) lng / 1E5)));     poly.add(p); } return poly; } 

   3.Add to map:

   PolylineOptions polylineOptions= new PolylineOptions(); polylineOptions.addAll(decodePoly(overview_polyline.points)); mGoogleMap.addPolyline(polylineOptions.width(5).color(Color.BLUE).geodesic(false)); 

文章来源: How to Add Snap to Roads Google Map in Android Studio