title: WPF ReactiveUI binding Listbox.ItemsSource to ReadOnlyObservableCollection not working
body: <p>In my WPF+ReactiveUI+DynamicData project I can't make binding of ListBox.ItemsSource to ReadOnlyObservableCollection working.
  I successfully populate data from by backend service to my ViewModel</p>
  <pre><code>public class RecordingsListViewModel: ReactiveObject
      {
          private readonly ReadOnlyObservableCollection&lt;RecordingViewModel&gt; _recordings;
          public ReadOnlyObservableCollection&lt;RecordingViewModel&gt; Recordings =&gt; _recordings;
  
          public RecordingsListViewModel(IRecordingsService recordindsService)
          {
              recordindsService.RecordingsList.Connect()
                  .Transform(rec =&gt; new RecordingViewModel(rec as IRecordingModel))
                  .Bind(out _recordings)
                  .Subscribe();
          }
      }
  </code></pre>
  <p>My View:</p>
  <pre><code>&lt;reactiveui:ReactiveUserControl x:Class=&quot;MyProject.Views.RecordingsListView&quot;
                                  x:TypeArguments=&quot;vm:RecordingsListViewModel&quot;
               xmlns=&quot;http://schemas.microsoft.com/winfx/2006/xaml/presentation&quot;
               xmlns:x=&quot;http://schemas.microsoft.com/winfx/2006/xaml&quot;
               xmlns:mc=&quot;http://schemas.openxmlformats.org/markup-compatibility/2006&quot; 
               xmlns:d=&quot;http://schemas.microsoft.com/expression/blend/2008&quot; 
               xmlns:vm=&quot;clr-namespace:MyProject.ViewModels&quot;
               xmlns:reactiveui=&quot;http://reactiveui.net&quot;
               mc:Ignorable=&quot;d&quot; 
               d:DesignHeight=&quot;450&quot; d:DesignWidth=&quot;800&quot;&gt;
  
      &lt;ListBox x:Name =&quot;RecordingsListBox&quot; HorizontalContentAlignment=&quot;Stretch&quot;/&gt;
  
  &lt;/reactiveui:ReactiveUserControl&gt;
  </code></pre>
  <p>In my code behind I'm trying to bind but it doesn't work</p>
  <pre><code>    {
          public static readonly DependencyProperty ViewModelProperty = DependencyProperty
          .Register(nameof(ViewModel), typeof(RecordingsListViewModel), typeof(RecordingsListView));
  
          public RecordingsListViewModel ViewModel
          {
              get =&gt; (RecordingsListViewModel)GetValue(ViewModelProperty);
              set =&gt; SetValue(ViewModelProperty, value);
          }
  
          object IViewFor.ViewModel
          {
              get =&gt; ViewModel;
              set =&gt; ViewModel = (RecordingsListViewModel)value;
          }
  
          public RecordingsListView()
          {
              ViewModel = Locator.Current.GetService&lt;RecordingsListViewModel&gt;();
              InitializeComponent();
  
              this.WhenActivated(d =&gt;
              {
                  this.OneWayBind(ViewModel,
                     vm =&gt; ViewModel.Recordings,
                     view =&gt; view.RecordingsListBox.ItemsSource).DisposeWith(d);
              });
          }
      }
  </code></pre>
  <p>There is an error in output, but it is not crashing app</p>
  <pre><code>PropertyBinderImplementation: view.RecordingsListBox.ItemsSource Binding received an Exception! - System.NotSupportedException: Unsupported expression of type 'Constant'. Did you miss the member access prefix in the expression?
     at ReactiveUI.ExpressionMixins.GetExpressionChain(Expression expression) in /_/src/ReactiveUI/Mixins/ExpressionMixins.cs:line 78
     at ReactiveUI.ReactiveNotifyPropertyChangedMixin.SubscribeToExpressionChain[TSender,TValue](TSender source, Expression expression, Boolean beforeChange, Boolean skipInitial, Boolean suppressWarnings) in /_/src/ReactiveUI/Mixins/ReactiveNotifyPropertyChangedMixin.cs:line 140
     at ReactiveUI.WhenAnyMixin.WhenAnyDynamic[TSender,TRet](TSender sender, Expression property1, Func`2 selector) in /_/src/ReactiveUI/VariadicTemplates.cs:line 99
     at ReactiveUI.Reflection.&lt;&gt;c__DisplayClass15_0`2.&lt;ViewModelWhenAnyValue&gt;b__2(Object x) in /_/src/ReactiveUI/Expression/Reflection.cs:line 407
     at System.Reactive.Linq.ObservableImpl.Select`2.Selector._.OnNext(TSource value) in /_/Rx.NET/Source/src/System.Reactive/Linq/Observable/Select.cs:line 39
  </code></pre>
  <p>I'm googling for this error and relevant examples for almost 16 hours, tried lots of code adjustments without any luck.
  Any ideas much appreciated</p>