updated repro design.

samples/XamlTestApplicationPcl/ViewModels/EditorViewModel.cs

@@ -1,4 +1,6 @@
-namespace XamlTestApplication.ViewModels
+using Perspex.Threading;
+
+namespace XamlTestApplication.ViewModels
 {
     using ReactiveUI;
     using System;
@@ -19,6 +21,12 @@
             {
                 Documents.Add(new EditorViewModel());
             });
+
+            GCCommand = ReactiveCommand.Create();
+            GCCommand.Subscribe(_ =>
+            {
+                GC.Collect();
+            });
         }
 
         public static ShellViewModel Instance = new ShellViewModel();
@@ -38,14 +46,28 @@
             set { this.RaiseAndSetIfChanged(ref selectedDocument, value); }
         }
 
+        private int instanceCount;
+
+        public int InstanceCount
+        {
+            get { return instanceCount; }
+            set { this.RaiseAndSetIfChanged(ref instanceCount, value); }
+        }
+
+
 
         public ReactiveCommand<object> AddDocumentCommand { get; }
+        public ReactiveCommand<object> GCCommand { get; }
     }
 
     public class EditorViewModel : ReactiveObject
     {
+        private static int InstanceCount = 0;
+
         public EditorViewModel()
         {
+            InstanceCount++;
+            ShellViewModel.Instance.InstanceCount = InstanceCount;
             text = "This is some text.";
 
             CloseCommand = ReactiveCommand.Create();
@@ -59,6 +81,14 @@
         ~EditorViewModel()
         {
             
+            
+            //System.Console.WriteLine("EVM Destructed");
+            InstanceCount--;
+            Dispatcher.UIThread.InvokeAsync(() =>
+            {
+                ShellViewModel.Instance.InstanceCount = InstanceCount;
+            });
+
         }
 
         private string text;

samples/XamlTestApplicationPcl/Views/MainWindow.xaml

@@ -381,7 +381,8 @@
             </TabStrip>
             <Grid Background="#007ACC" Height="2" />
               <Button Content="AddTab" Command="{Binding AddDocumentCommand}" Width="50" Height="30" />
-          
+              <Button Content="GC.Collecy" Command="{Binding GCCommand}" Width="50" Height="30" />
+              <TextBox Text="{Binding InstanceCount}"           />
 
           <Carousel Items="{Binding Documents}" SelectedIndex="{Binding #strip.SelectedIndex}" IsVirtualized="false">
             <Carousel.DataTemplates>