Will Pittenger

    public partial class ComboBox : System.Windows.Controls.ComboBox, System.ComponentModel.INotifyPropertyChanged
    {
        #region Constructors & Destructors
            public ComboBox()
            {
                ItemsSource = entries = new System.Collections.Generic.List<OneEntry>();

                InitializeComponent();
            }
        #endregion

        #region Events
            public event System.ComponentModel.PropertyChangedEventHandler PropertyChanged;
        #endregion

        #region Constants
            private static class PropNames
            {
                public const string strEnumType = "EnumType";
            }
        #endregion

        #region Helper Types
            private class OneEntry
            {
                #region Constructors & Deconstructors
                    public OneEntry(object enumVal, string strDisplayText, string strTooltipText)
                    {
                        System.Diagnostics.Debug.Assert(enumVal.GetType().IsEnum);

                        this.enumVal = enumVal;
                        this.strDisplayText = strDisplayText;
                        this.strTooltipText = strTooltipText;
                    }
                #endregion

                #region Members
                    private readonly object enumVal;
                    private readonly string strDisplayText;
                    private readonly string strTooltipText;
                #endregion

                #region Properties
                    public object EnumVal => enumVal;
                    public string DisplayText => strDisplayText;
                    public string TooltipText => strTooltipText;
                #endregion
            }
        #endregion

        #region Members
            #region Dependency Properties
                public static readonly System.Windows.DependencyProperty EnumTypeProperty = System.Windows.DependencyProperty.Register(PropNames.strEnumType,
                    typeof(string), typeof(ComboBox), new System.Windows.PropertyMetadata(OnEnumTypePropChanged));
            #endregion

            private System.Type typeOfEnum = null;

            private System.Collections.Generic.List<OneEntry> entries;
        #endregion

        #region Properties
            [System.ComponentModel.Description("This is the enum type that the items are based on.  Each one must have Org.WillPittenger.AdBlockPlusIniParserWPF.Core.Attr"
                + ".LocalizedDescAttribute applied to it.")]
            [System.ComponentModel.Category("Common")]
            public string EnumType
            {
                get => (string)GetValue(EnumTypeProperty);

                set => SetValue(EnumTypeProperty, value);
            }
        #endregion

        #region Methods
            private void GetEnumDesc(object objEnumValue, out string strDesc, out string strExtendedDesc)
            {
                System.Reflection.FieldInfo fieldInfo = objEnumValue.GetType().GetField(objEnumValue.ToString());

                object[] attribArray = fieldInfo.GetCustomAttributes(typeof(Attr.LocalizedDescAttribute), false);

                if(attribArray.Length == 0)
                {
                    strDesc = objEnumValue.ToString();
                    strExtendedDesc = "";
                }
                else
                {
                    Attr.LocalizedDescAttribute attrib = attribArray[0] as Attr.LocalizedDescAttribute;

                    strDesc = attrib.Desc;
                    strExtendedDesc = attrib.ExtendedDesc;
                }
            }
        #endregion

        #region Event Handlers
            private void OnEnumTypePropChanged(string strNewVal)
            {
                System.Type typeProposed = System.Type.GetType(strNewVal);

                if(typeProposed == typeOfEnum)
                    return;

                if(typeProposed == null || !typeProposed.IsEnum)
                    return;

                typeOfEnum = typeProposed;

                entries.Capacity = typeOfEnum.GetEnumValues().Length;

                foreach(object objCurValInEnumType in typeOfEnum.GetEnumValues())
                {
                    GetEnumDesc(objCurValInEnumType, out string strText, out string strTooltip);

                    entries.Add(new OneEntry(objCurValInEnumType, strText, strTooltip));
                }

                UpdateLayout();
            }

            private static void OnEnumTypePropChanged(System.Windows.DependencyObject ctrlParent, System.Windows.DependencyPropertyChangedEventArgs e) =>
                ((ComboBox)ctrlParent).OnEnumTypePropChanged((string)e.NewValue);

            protected override void OnSelectionChanged(System.Windows.Controls.SelectionChangedEventArgs e) => base.OnSelectionChanged(e);
        #endregion
    }