public virtual void DidSelectFeaturesWithFeatureSet(AGSFeatureLayer featureLayer, NSOperation op, AGSFeatureSet featureSet)
        {
            AGSMutableEnvelope env = null;

            foreach (var selectedFature in featureSet.Features)
            {
                if (env != null)
                {
                    env.UnionWithEnvelope(selectedFature.Geometry.Envelope);
                }
                else
                {
                    env = (AGSMutableEnvelope)selectedFature.Geometry.Envelope.MutableCopy();
                }
            }
            this.MapView.ZoomToGeometry(env, 20, true);
        }
		public virtual void DidSelectFeaturesWithFeatureSet(AGSFeatureLayer featureLayer, NSOperation op, AGSFeatureSet featureSet) {
			AGSMutableEnvelope env = null;
			foreach (var selectedFature in featureSet.Features) {
				if (env != null) {
					env.UnionWithEnvelope(selectedFature.Geometry.Envelope);
				}
				else {
					env = (AGSMutableEnvelope)selectedFature.Geometry.Envelope.MutableCopy();
				}
			}
			this.MapView.ZoomToGeometry(env, 20, true);
		}