MapPolyline.Path.Add doesn't work

Question

I used this code for my app:

var line = new MapPolyline();
line.StrokeColor = Colors.Red;
line.StrokeThickness = 2;
line.Path.Add(new GeoCoordinate(lat,long));   //<== this
line.Path.Add(new GeoCoordinate(lat, long));  //<== and this
MyMap.MapElements.Add(line);

I used Windows phone 8.1 At the marked locations receive this error:

'Windows.Devices.Geolocation.Geopath' does not contain a definition for 'Add' and no extension method 'Add' accepting a first argument of type 'Windows.Devices.Geolocation.Geopath' could be found (are you missing a using directive or an assembly reference?)

What to do to work??

P.S. I have using Windows.Devices.Geolocation;

Answer 1

That's right. You have to generate the list separately and pass it using the constructor:

List<BasicGeoposition> positions = new List<BasicGeoposition>();
// Now add your positions:
positions.Add(new BasicGeoposition(){ Latitude = lat, Longitude = long});   //<== this
positions.Add(new BasicGeoposition(){ Latitude = lat, Longitude = long));  //<== and this
Geopath path = new Geopath(positions);
var line = new MapPolyline();
// Set your path
line.Path = path;
line.StrokeColor = Colors.Red;
line.StrokeThickness = 2;
MyMap.MapElements.Add(line);

I know - it's a bit tricky. But I think the purpose is that you can't manipulate the path once the polygon is drawn on the map.