android-how to remove lines on map

Question

I'm drawing lines between two position on map and it works fine .

I need to remove them when I want to draw new line . This is my code :

PolylineOptions lineOptions;
ArrayList<LatLng> points = null;
for(int i=0;i<result.size();i++){
                    points = new ArrayList<LatLng>();
                    List<HashMap<String, String>> path = result.get(i);
                    for(int j=0;j<path.size();j++){
                        HashMap<String,String> point = path.get(j); 
                        if(j==0){   
                            distance = (String)point.get("distance");                       
                            continue;
                        }else if(j==1){
                            duration = (String)point.get("duration");
                            continue;
                        }
                        double lat = Double.parseDouble(point.get("lat"));
                        double lng = Double.parseDouble(point.get("lng"));
                        LatLng position = new LatLng(lat, lng); 
                        points.add(position);                       
                    }
                }
lineOptions.addAll(points);
            lineOptions.width(3);
            lineOptions.color(Color.RED);
map.addPolyline(lineOptions);

I tried map.clear() , didn't work . How can I clear all lines on the map ?

thanks you

Answer 1

Make an ArrayList

ArrayList<Polyline> polylineArraylist;

In onCreate Method

polylineArraylist = new ArrayList<Polyline>();

Update your code with this one

// flusing all Markers drawn previously
for (int icount = 0; icount < polylineArraylist.size(); icount++) {
Polyline polyline = polylineArraylist.get(icount);
polyline.remove();
}

Polyline mPolyline = null;
PolylineOptions lineOptions;
ArrayList<LatLng> points = null;
for(int i=0;i<result.size();i++){
                    points = new ArrayList<LatLng>();
                    List<HashMap<String, String>> path = result.get(i);
                    for(int j=0;j<path.size();j++){
                        HashMap<String,String> point = path.get(j); 
                        if(j==0){   
                            distance = (String)point.get("distance");                       
                            continue;
                        }else if(j==1){
                            duration = (String)point.get("duration");
                            continue;
                        }
                        double lat = Double.parseDouble(point.get("lat"));
                        double lng = Double.parseDouble(point.get("lng"));
                        LatLng position = new LatLng(lat, lng); 
                        points.add(position);                       
                    }
                }
lineOptions.addAll(points);
            lineOptions.width(3);
            lineOptions.color(Color.RED);
mPolyline = googleMap.addPolyline(lineOptions);

Add Polyline to ArrayList

polylineArraylist.add(mPolyline);