c# - ComboBox Won't Change Item Displayed -

so follow tutorial link it's tutorial allow spaces in combo boxes itemssource list of enum. tutorial worked , explained well. issue i'm having , wondering if help, when choose display lets software engineer , later decide should team lead not change. remains software engineer, i'm wondering how abouts fix this?

namespace caliburnmicrodemo1 { public class enumhelper : dependencyobject {     public static type getenum(dependencyobject obj)     {         return (type)obj.getvalue(enumproperty);     }      public static void setenum(dependencyobject obj, string value)     {         obj.setvalue(enumproperty, value);     }      // using dependencyproperty backing store enum.  enables animation, styling, binding, etc...     public static readonly dependencyproperty enumproperty =         dependencyproperty.registerattached("enum", typeof(type), typeof(enumhelper), new propertymetadata(null, onenumchanged));      private static void onenumchanged(dependencyobject sender, dependencypropertychangedeventargs e)     {         var control = sender itemscontrol;          if (control != null)         {             if (e.newvalue != null)             {                 var _enum = enum.getvalues(e.newvalue type);                 control.itemssource = _enum;             }         }     }      public static bool getmoredetails(dependencyobject obj)     {         return (bool)obj.getvalue(moredetailsproperty);     }      public static void setmoredetails(dependencyobject obj, bool value)     {         obj.setvalue(moredetailsproperty, value);     }      // using dependencyproperty backing store moredetails.  enables animation, styling, binding, etc...     public static readonly dependencyproperty moredetailsproperty =         dependencyproperty.registerattached("moredetails", typeof(bool), typeof(enumhelper), new propertymetadata(false, onmoredetailschanged));      private static void onmoredetailschanged(dependencyobject sender, dependencypropertychangedeventargs e)     {         var control = sender frameworkelement;         if (control != null)         {             var enumobject = control.datacontext;             var fieldinfo = enumobject.gettype().getfield(enumobject.tostring());              var array = fieldinfo.getcustomattributes(false);              if (array.length == 0)             {                 if (control textblock)                 {                     ((textblock)control).text = enumobject.tostring();                 }                 else if (control contentcontrol)                 {                     ((contentcontrol)control).content = enumobject;                 }                 return;             }              foreach (var o in array)             {                 if (o descriptionattribute)                 {                     control.tooltip = ((descriptionattribute) o).description;                 }                 else if (o displayattribute)                 {                     if (control textblock)                     {                         ((textblock) control).text = ((displayattribute) o).name;                     }                     else if (control contentcontrol)                     {                         ((contentcontrol)control).content = ((displayattribute)o).name;                     }                 }             }         }     } } }   enum:  public enum designation {     [display(name="software engineer")]     [description("software engineer responsible core development.")]     softwareengineer,     [display(name = "team lead")]     [description("team lead responsible leading small team of 5 10 members.")]     teamlead,     [display(name = "product manager")]     [description("product manager responsible core management.")]     productmanager }