Gets a value that indicates whether this XamlType is built top-down during XAML initialization.
Assembly: System.Xaml (in System.Xaml.dll)
Top-down is a metaphor that approximates XAML processor behavior when creating the object graph. When built top-down, a type is instantiated, attached to the parent, and then has its properties set. Top-down construction avoids invoking property-changed handlers multiple times. Such handling ripples up the object graph and therefore, eliminates the multiple handler calls and provides a performance optimization for startup of the object graph.
If you do not use the default internal CLR reflection technique for a XamlType, calls to this property can invoke LookupUsableDuringInitialization overrides on XamlType derived classes. For more information about return values and other behavior, see the documentation for LookupUsableDuringInitialization on this type.