PropertyGrid: implemented PropertyOrderAttribute. You can now apply the PropertyOrder attirbute to a property to control the order in which the properties are sorted. The attribute is only honored while in the Categorized view and ignored when sorted alphabetically

ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/PropertyGrid/Implementation/Attributes/PropertyOrderAttribute.cs

@@ -0,0 +1,15 @@
+using System;
+
+namespace Microsoft.Windows.Controls.PropertyGrid.Attributes
+{
+    [AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
+    public class PropertyOrderAttribute : Attribute
+    {
+        public int Order { get; set; }
+        
+        public PropertyOrderAttribute(int order)
+        {
+            Order = order;
+        }
+    }
+}

ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/PropertyGrid/Implementation/PropertyGridUtilities.cs

@@ -33,6 +33,7 @@ namespace Microsoft.Windows.Controls.PropertyGrid
             PropertyItemCollection propertyCollection = new PropertyItemCollection(propertyItems);
             propertyCollection.GroupBy("Category");
             propertyCollection.SortBy("Category", ListSortDirection.Ascending);
+            propertyCollection.SortBy("PropertyOrder", ListSortDirection.Ascending);
             propertyCollection.SortBy("DisplayName", ListSortDirection.Ascending);
             return propertyCollection;
         }

ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/PropertyGrid/Implementation/PropertyItem.cs

@@ -254,6 +254,8 @@ namespace Microsoft.Windows.Controls.PropertyGrid
 
         public PropertyGrid PropertyGrid { get; private set; }
 
+        public int PropertyOrder { get; set; } //maybe make a DP
+
         #region PropertyType
 
         public Type PropertyType
@@ -325,6 +327,7 @@ namespace Microsoft.Windows.Controls.PropertyGrid
 
             SetPropertyDescriptorProperties();
             ResolveExpandableObject();
+            ResolvePropertyOrder();
 
             CommandBindings.Add(new CommandBinding(PropertyItemCommands.ResetValue, ExecuteResetValueCommand, CanExecuteResetValueCommand));
             AddHandler(Mouse.PreviewMouseDownEvent, new MouseButtonEventHandler(PropertyItem_PreviewMouseDown), true);
@@ -402,6 +405,15 @@ namespace Microsoft.Windows.Controls.PropertyGrid
             }
         }
 
+        private void ResolvePropertyOrder()
+        {
+            var attrs = PropertyDescriptor.Attributes.OfType<PropertyOrderAttribute>();
+            if (attrs.Any())
+                PropertyOrder = attrs.First().Order;
+            else
+                PropertyOrder = 0;
+        }
+
         private void SetPropertyDescriptorProperties()
         {
             Name = PropertyDescriptor.Name;

ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/WPFToolkit.Extended.csproj

@@ -274,6 +274,7 @@
     <Compile Include="PropertyGrid\Implementation\Attributes\ExpandableObjectAttribute.cs" />
     <Compile Include="PropertyGrid\Implementation\Attributes\IItemsSource.cs" />
     <Compile Include="PropertyGrid\Implementation\Attributes\ItemsSourceAttribute.cs" />
+    <Compile Include="PropertyGrid\Implementation\Attributes\PropertyOrderAttribute.cs" />
     <Compile Include="PropertyGrid\Implementation\Commands\PropertyGridCommands.cs" />
     <Compile Include="PropertyGrid\Implementation\Converters\ValueSourceToImagePathConverter.cs" />
     <Compile Include="PropertyGrid\Implementation\Converters\ValueSourceToToolTipConverter.cs" />