MapPoint P = new MapPoint(i_lt, i_lon);//,new SpatialReference(102100));
Graphic graphic = new Graphic()
{
Geometry = P,// mercator.FromGeographic(P),
MapPoint P = new MapPoint(i_lt, i_lon,new SpatialReference(4326));
Graphic graphic = new Graphic()
{
Geometry = mercator.FromGeographic(P),