我试图删除previously增加折线，当位置已经改变重绘新的折线。我想这两个

this.routeToDestination.setPoints（pointsToDestination）和    this.routeToDestination.remove（）

但他们都没有工作。

我也跟着How绘制与谷歌地图Android版API V2 动态线（路线），但未能解决该问题。

  @覆盖    公共无效onResume（）{        super.onResume（）;        routeToDestination = mMap.addPolyline（新的PolylineOptions（）                。新增（新经纬度（location.getLatitude（），location.getLongitude（）），                        新的经纬度（this.destinationLatitude，this.destinationLongitude））                .WIDTH（1）                。颜色（Color.DKGRAY）        ）;    }   @覆盖    公共无效onLocationChanged（地点）{        清单＆LT;＆经纬度GT; pointsToDestination =新的ArrayList＆LT;＆经纬度GT;（）;        pointsToDestination.add（新经纬度（location.getLatitude（），location.getLongitude（）））;        pointsToDestination.add（新经纬度（destinationLatitude，destinationLongitude））;        this.routeToDestination.setPoints（pointsToDestination）;    }} 

解决方案

要删除您只需要使用remove（）方法的API中所述的折线。

  //添加行地图折线行= mMap.addPolyline（新的PolylineOptions（）            。新增（新经纬度（location.getLatitude（），location.getLongitude（）），                    新的经纬度（this.destinationLatitude，this.destinationLongitude））            .WIDTH（1）            。颜色（Color.DKGRAY）//删除从地图中的同一行line.remove（）; 

I am trying to remove previously added Polyline and redraw new Polyline when the location has been changed. I tried both

this.routeToDestination.setPoints(pointsToDestination) and this.routeToDestination.remove()

but neither of them worked.

I followed How to draw a dynamic line (route) with Google Maps Android API v2 but could not resolved the issue

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

        routeToDestination = mMap.addPolyline(new PolylineOptions()
                .add(new LatLng(location.getLatitude(), location.getLongitude()),
                        new LatLng(this.destinationLatitude, this.destinationLongitude))
                .width(1)
                .color(Color.DKGRAY)

        );
    }

   @Override
    public void onLocationChanged(Location location) {

        List<LatLng> pointsToDestination = new ArrayList<LatLng>();
        pointsToDestination.add(new LatLng(location.getLatitude(), location.getLongitude()));
        pointsToDestination.add(new LatLng(destinationLatitude, destinationLongitude));

        this.routeToDestination.setPoints(pointsToDestination);
    }

}

To remove a polyline you should simply use remove() method as stated in the API.

//Add line to map
Polyline line = mMap.addPolyline(new PolylineOptions()
            .add(new LatLng(location.getLatitude(), location.getLongitude()),
                    new LatLng(this.destinationLatitude, this.destinationLongitude))
            .width(1)
            .color(Color.DKGRAY)

//Remove the same line from map
line.remove();