When designing custom controls we would want the users to customize the appearance of the items that is added up in some derived form of ItemsControl. Say we have a property “ItemContainerStyle”, we would want that to be customized in Blend as it does for ListBox,
Lets say, we have a property called “MyButtonStyle”. To enable this property to be recognized by the designer, we would have to implement the StyleTypedPropertyAttribute in the implemented class,
[StyleTypedProperty(Property = "MyButtonStyle", StyleTargetType = typeof(MyButton))]
public class MyButtonItems: ItemsControl
That’s it. Hope this helps.