public App() { App.Self = this; ChangedClass = new ChangedEvent(); // we need give the co-ordinates an initial value Longitude = 53.431; Latitude = -2.956; this.ChangedClass.Change += (object s, ChangedEventArgs ea) => { if (ea.ModuleName == "location") { var locdata = ea.Id.Split(',').ToArray(); Longitude = double.Parse(locdata[1]); Latitude = double.Parse(locdata[0]); ChangedClass.BroadcastIt("updated-location", "."); } }; MainPage = new MapPage(); }