Latest Contributions by JoeHershman

Would seem you need to tell the HttpClient to use DefaultCredentials using HttpClient httpClient = new HttpClient(new HttpClientHandler{UseDefaultCredentials = true});   ... View more

I tend to always wonder why someone doesn't want to use an external MVVM library, but that is a conversation for another day. Without an external library generally, one would want to roll their own delegate command ICommand implementation which is pretty straight forward public class DelegateCommand : ICommand { private readonly Predicate<object> _canExecute; private readonly Action<object> _execute; public DelegateCommand(Action<object> execute) : this(execute, null) { } public DelegateCommand(Action<object> execute, Predicate<object> canExecute) { _execute = execute; _canExecute = canExecute; } #region ICommand Members public event EventHandler CanExecuteChanged; public bool CanExecute(object parameter) { return _canExecute == null || _canExecute(parameter); } public void Execute(object parameter) { _execute(parameter); } #endregion public void RaiseCanExecuteChanged() { CanExecuteChanged?.Invoke(this, EventArgs.Empty); } } With this one can just create an ICommand and pass the action into this DelegateCommand. To simplify the MainWindow Xaml, instead of making the view model a static resource, bind it as the DataContext.  By doing this one does not need to set the source of the binding, it will be the defined DatContext <Window x:Class="WpfApp2.MainWindow" ... xmlns:local="clr-namespace:WpfApp2" xmlns:esri="http://schemas.esri.com/arcgis/runtime/2013" mc:Ignorable="d" Title="MainWindow" Height="450" Width="800" > <Window.DataContext> <local:MapViewModel /> </Window.DataContext> <Grid> <esri:MapView Map="{Binding Map}" x:Name="mapView" /> <!-- Command is bound to ICommand on ViewModel --> <Button Content="Add Layer" Command="{Binding AddLayerCommand}" Height="40" Width="80" Margin="10,10,0,0" HorizontalAlignment="Left" VerticalAlignment="Top"/> </Grid> </Window> Now we just wire up our ViewModel public class MapViewModel : INotifyPropertyChanged { public MapViewModel() { CreateNewMap(); } private void CreateNewMap() { //For sample using the viewpoint of the layer in code, // personally I would not set an initial extent from a feature layer that needed to load at startup, // but that's also a conversation for another day var targetGeometry = Geometry.FromJson( "{\"xmin\":-13240129.679701095,\"ymin\":3994281.9887753138,\"xmax\":-13106722.92583799,\"ymax\":4101417.5063218847,\"spatialReference\":{\"wkid\":102100,\"latestWkid\":3857}}"); Map = new Map(Basemap.CreateImageryWithLabels()) { InitialViewpoint = new Viewpoint(targetGeometry!) }; Map.Loaded += (sender, args) => { Console.WriteLine("all done loading"); }; } private Map _map; public Map Map { get => _map; set { _map = value; OnPropertyChanged(nameof(Map)); } } //So here just create a DelegateCommand passing in the delegate, it will execute when invoked public ICommand AddLayerCommand => new DelegateCommand(ExecuteAddLayer); //As pointed out by Morten, generally an async should return a Task, // In this situation void is proper because it is a Delegate command private async void ExecuteAddLayer(object obj) { try { var trailHeadsLayer = new FeatureLayer(new Uri("https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Trailheads/FeatureServer/0")); await trailHeadsLayer.LoadAsync(); Map.OperationalLayers.Add(trailHeadsLayer); await Map.LoadAsync(); } catch (Exception e) { Console.WriteLine(e); } } //remove INotifyPropertyChanged for sample purposes } ... View more