WPF Propertygrid with custom sorting

Question

Ordering of properties in the Extended WPF Toolkit can be achieved by decorating the property with the PropertyOrderAttribute attribute.

If you don't want to pollute POCO's by decorating them with attributes at design time, or the order is dynamic in some way, then it's possible to add the attribute at run time by creating a type converter and overriding the GetProperties method. For example, if you wish to maintain the index order of a generic IList type:

using Xceed.Wpf.Toolkit.PropertyGrid.Attributes;
using System.ComponentModel;

 public class MyExpandableIListConverter<T> : ExpandableObjectConverter
{
    public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext context, object value, Attribute[] attributes)
    {
        if (value is IList<T>)
        {
            IList<T> list = value as IList<T>; 
            PropertyDescriptorCollection propDescriptions = new PropertyDescriptorCollection(null);
            IEnumerator enumerator = list.GetEnumerator();
            int counter = -1;
            while (enumerator.MoveNext())
            {
                counter++;
                propDescriptions.Add(new ListItemPropertyDescriptor<T>(list, counter));

            }
            return propDescriptions;
        }
        else
        {
            return base.GetProperties(context, value, attributes);
        }
    }        
}

With the ListItemPropertyDescriptor being defined as follows:

using Xceed.Wpf.Toolkit.PropertyGrid.Attributes;
using System.ComponentModel;

public class ListItemPropertyDescriptor<T> : PropertyDescriptor
{
    private readonly IList<T> owner;
    private readonly int index;

    public ListItemPropertyDescriptor(IList<T> owner, int index) : base("["+ index+"]", null)
    {
        this.owner = owner;
        this.index = index;

    }

    public override AttributeCollection Attributes
    {
        get
        {
            var attributes = TypeDescriptor.GetAttributes(GetValue(null), false);
            //If the Xceed expandable object attribute is not applied then apply it
            if (!attributes.OfType<ExpandableObjectAttribute>().Any())
            {
                attributes = AddAttribute(new ExpandableObjectAttribute(), attributes);
            }

            //set the xceed order attribute
            attributes = AddAttribute(new PropertyOrderAttribute(index), attributes);

            return attributes;
        }
    }
    private AttributeCollection AddAttribute(Attribute newAttribute, AttributeCollection oldAttributes)
    {
        Attribute[] newAttributes = new Attribute[oldAttributes.Count + 1];
        oldAttributes.CopyTo(newAttributes, 1);
        newAttributes[0] = newAttribute;

        return new AttributeCollection(newAttributes);
    }

    public override bool CanResetValue(object component)
    {
        return false;
    }

    public override object GetValue(object component)
    {
        return Value;
    }

    private T Value
      => owner[index];

    public override void ResetValue(object component)
    {
        throw new NotImplementedException();
    }

    public override void SetValue(object component, object value)
    {
        owner[index] = (T)value;
    }

    public override bool ShouldSerializeValue(object component)
    {
        return false;
    }

    public override Type ComponentType
      => owner.GetType();

    public override bool IsReadOnly
      => false;

    public override Type PropertyType
      => Value?.GetType();

}

Portions of this code were adapted from the following SO answer