如何在.NET PropertyGrid中显示具有重复值的枚举？

public enum MyEnum
{
    [Description("Value 1")]
    Value1 = 1,
    [Description("Value 2")]
    Value2 = 2,
    [Description("Value 3")]
    Value3 = 2, // 与Value2具有相同的值
    [Description("Value 4")]
    Value4 = 3
}

public class MyEnumPropertyDescriptor : PropertyDescriptor
{
    private Type enumType;

    public MyEnumPropertyDescriptor(Type componentType, string name, Type enumType)
        : base(name, null)
    {
        this.enumType = enumType;
    }

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

    public override Type ComponentType
    {
        get { return typeof(MyEnum); }
    }

    public override object GetValue(object component)
    {
        MyEnum value = (MyEnum)component;
        return value.ToString();
    }

    public override bool IsReadOnly
    {
        get { return false; }
    }

    public override Type PropertyType
    {
        get { return enumType; }
    }

    public override void ResetValue(object component)
    {
        // 不需要实现
    }

    public override void SetValue(object component, object value)
    {
        MyEnum newValue;
        if (Enum.TryParse(value.ToString(), out newValue))
        {
            component = newValue;
        }
    }

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

private void Form_Load(object sender, EventArgs e)
{
    TypeDescriptor.AddAttributes(typeof(MyEnum), new TypeConverterAttribute(typeof(MyEnumPropertyDescriptor)));
    propertyGrid1.SelectedObject = myObject; // myObject是包含枚举属性的对象
}