Merge pull request #108 from LukeOrdelmans/bugfix/fix-property-change…

…d-event-handler-deregistration-on-rendertransformoriginextension

Bugfix/fix property changed event handler deregistration on RenderTransformOriginExtension

WpfDesign.Designer/Project/Extensions/RenderTransformOriginExtension.cs

@@ -18,6 +18,7 @@
 
 using System;
 using System.ComponentModel;
+using System.Threading;
 using ICSharpCode.WpfDesign.Adorners;
 using ICSharpCode.WpfDesign.Extensions;
 using System.Windows.Controls.Primitives;
@@ -33,8 +34,7 @@ public class RenderTransformOriginExtension : SelectionAdornerProvider
 	{
 		readonly AdornerPanel adornerPanel;
 		RenderTransformOriginThumb renderTransformOriginThumb;
-		/// <summary>An array containing this.ExtendedItem as only element</summary>
-		readonly DesignItem[] extendedItemArray = new DesignItem[1];
+
 //		IPlacementBehavior resizeBehavior;
 //		PlacementOperation operation;
 //		ChangeGroup changeGroup;
@@ -86,7 +86,6 @@ void renderTransformOriginThumb_DragDelta(object sender, DragDeltaEventArgs e)
 		protected override void OnInitialized()
 		{
 			base.OnInitialized();
-			extendedItemArray[0] = this.ExtendedItem;
 			this.ExtendedItem.PropertyChanged += OnPropertyChanged;
 
 			if (this.ExtendedItem.Properties.GetProperty(FrameworkElement.RenderTransformOriginProperty).IsSet) {
@@ -116,6 +115,7 @@ void OnPropertyChanged(object sender, System.ComponentModel.PropertyChangedEvent
 
 		protected override void OnRemove()
 		{
+			this.ExtendedItem.PropertyChanged -= OnPropertyChanged;
 			renderTransformOriginPropertyDescriptor.RemoveValueChanged(this.ExtendedItem.Component, OnRenderTransformOriginPropertyChanged);
 
 			base.OnRemove();