From 6682b09bd9b2c25049480126c64670795fad6711 Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Sat, 5 Mar 2016 15:29:47 +0100
Subject: [PATCH] Unsub from classes when removed from logical tree.

---
 src/Perspex.Diagnostics/ViewModels/TreeNode.cs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/Perspex.Diagnostics/ViewModels/TreeNode.cs b/src/Perspex.Diagnostics/ViewModels/TreeNode.cs
index 62044d2a28..179e365b4c 100644
--- a/src/Perspex.Diagnostics/ViewModels/TreeNode.cs
+++ b/src/Perspex.Diagnostics/ViewModels/TreeNode.cs
@@ -6,6 +6,7 @@ using System.Collections.Specialized;
 using System.Reactive;
 using System.Reactive.Linq;
 using Perspex.Controls;
+using Perspex.Styling;
 using ReactiveUI;
 
 namespace Perspex.Diagnostics.ViewModels
@@ -25,7 +26,8 @@ namespace Perspex.Diagnostics.ViewModels
                     NotifyCollectionChangedEventHandler, 
                     NotifyCollectionChangedEventArgs>(
                 x => control.Classes.CollectionChanged += x,
-                x => control.Classes.CollectionChanged -= x);
+                x => control.Classes.CollectionChanged -= x)
+                .TakeUntil(((IStyleable)control).StyleDetach);
 
             classesChanged.Select(_ => Unit.Default)
                 .StartWith(Unit.Default)