如何绑定用户控件属性？

Question

我有以下型号：

public class Customer
{
    public int Id {get; set;}
    public string Name {get; set;}
    public CategoryType Category {get; set;}
}

public class CategoryType
{
    public int Id {get; set;}
    public string Name {get; set;}
}

类别类型的用户控件：

[DefaultBindingProperty("Value")]
public partial class CategoryTypeControl : UserControl
{
    public class ValueChangedEventArgs
    {
        public T OldValue { get; private set; }
        public T NewValue { get; private set; }

        internal ValueChangedEventArgs(T oldValue, T newValue)
        {
            this.OldValue = oldValue;
            this.NewValue = newValue;
        }
    }
    public delegate void ValueChangedEventHandler(object sender, ValueChangedEventArgs e);
    public event ValueChangedEventHandler ValueChanged = delegate { };

    private CategoryType value;

    [Bindable(BindableSupport.Yes, BindingDirection.TwoWay)]
    public virtual CategoryType Value
    {
        get { return value; }
        set 
        {
            ValueChanged(this, new ValueChangedEventArgs(this.value, value));
            this.value = value; 
        }
    }
}

Customer表单的绑定源绑定到上述Customer模型，Customer.CategoryType绑定到CategoryTypeControl.Value。这是在设计模式下完成的，生成的代码是：

this.categoryType.DataBindings.Add(new System.Windows.Forms.Binding("Value", this.bindingSource, "CategoryType", true));

问题是，当用户从控件中选择类别类型时，模型的CategorType属性不会更新。

这不是绑定用户控件属性的正确方法吗？