I'm more or less looking for a best way to provide some of the common functionality for an UltraTextEditor in my application.  I wanted the functionality to draw the rounded corners of the text box from another post on the forums so I'd thought I'd subclass the text box.

However, I want a different appearance when the control has focus.  So to do this a different border colour will be used.  The following code provides this functionality, but the way I create the Appearance in the constructor, and the visibility of the Appearances collection, the designer generates the code for this appearance in a form.    It throws the following exception when the program is executed - as the Appearances is auto-generated:

An error occurred creating the form. See Exception.InnerException for details.  The error is: Key already exists

I am looking for a best practice on how to handle my appearances - or other setting of other properties in the subclass.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Infragistics.Documents.Reports.Graphics;
using Infragistics.Win;
using Infragistics.Win.UltraWinEditors;
 
namespace MyApp.Win.Controls
{
    public class WMSUltraTextEditor : UltraTextEditor
    {
        private AppearanceBase defaultAppearence;
        
        public WMSUltraTextEditor()
        {
            Appearance appearenceFocus = new Appearance();
            appearenceFocus.BorderColor = System.Drawing.Color.Green;
            appearenceFocus.Key = "Focus";
            this.Appearances.Add(appearenceFocus);
            this.BorderStyle = Infragistics.Win.UIElementBorderStyle.Rounded3;
            this.UseOsThemes = DefaultableBoolean.False;
        }
        protected override void OnCreateControl()
        {
            base.OnCreateControl();
            FixBorder();
            defaultAppearence = this.Appearance;
        }
 
        private void FixBorder()
        {
            System.Drawing.Rectangle textRect = new System.Drawing.Rectangle(System.Drawing.Point.Empty, this.Size);
            this.Region = DrawUtility.CreateBorderRegion(textRect, this.BorderStyle);
        }
 
        protected override void OnResize(EventArgs e)
        {
            base.OnResize(e);
            FixBorder();
        }
 
        protected override void OnEnter(EventArgs e)
        {
            this.Appearance = this.Appearances["Focus"];
            base.OnEnter(e);
        }
 
        protected override void OnLeave(EventArgs e)
        {
            base.OnLeave(e);
            this.Appearance = defaultAppearence;
        }
    }
}

Any thoughts?

Thanks

Andez