Export (0) Print
Expand All

XamlType.LookupUsableDuringInitialization Method

Returns a value that indicates whether this XamlType is built top-down during XAML initialization.

Namespace:  System.Xaml
Assembly:  System.Xaml (in System.Xaml.dll)

protected virtual bool LookupUsableDuringInitialization()

Return Value

Type: System.Boolean
true if this XamlType is built top-down during XAML initialization; otherwise, false.

Top-down is a metaphor that approximates XAML processor behavior when it creates the object graph. When built top-down, a type is instantiated, attached to the parent, and 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.

This method can be invoked by calls to IsUsableDuringInitialization.

The default implementation returns a value based on reading UsableDuringInitializationAttribute. It can also check BaseType for the attribute if no attribute is found on the immediate underlying type. If a value is unavailable, it returns false.

Override this method if you want IsUsableDuringInitialization to use different logic.

.NET Framework

Supported in: 4.5, 4

.NET Framework Client Profile

Supported in: 4

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

© 2014 Microsoft