UsableDuringInitializationAttribute Class
Definition
Important
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Indicates whether this type is built top-down during XAML object graph creation.
public ref class UsableDuringInitializationAttribute sealed : Attribute[System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=false, Inherited=true)]
public sealed class UsableDuringInitializationAttribute : Attribute[<System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=false, Inherited=true)>]
type UsableDuringInitializationAttribute = class
inherit AttributePublic NotInheritable Class UsableDuringInitializationAttribute
Inherits Attribute- Inheritance
- Attributes
Remarks
Top-down is a metaphor that approximates XAML processor behavior when creating the object graph. When built top-down, a class is instantiated, attached to the parent, and then has its properties set. Top-down construction avoids invoking property-changed handlers multiple times. Such handling will ripple up the object graph and therefore eliminating the multiple handler calls provides a performance optimization for startup of the object graph.
In previous versions of the .NET Framework, this class existed in the WPF-specific assembly WindowsBase. In .NET Framework 4, UsableDuringInitializationAttribute is in the System.Xaml assembly. For more information, see Types Migrated from WPF to System.Xaml.
WPF Usage Notes
In WPF XAML for .NET Framework 3.0 and .NET Framework 3.5, top-down construction was built in to the XAML processing for certain classes. The UsableDuringInitializationAttribute attribute formalizes the reporting of the top-down behavior in .NET Framework 4.
Constructors
| UsableDuringInitializationAttribute(Boolean) |
Initializes a new instance of the UsableDuringInitializationAttribute class. |
Properties
| TypeId |
When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute) |
| Usable |
Gets a value that indicates whether the associated class is usable during initialization. |
Methods
| Equals(Object) |
Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute) |
| GetHashCode() |
Returns the hash code for this instance. (Inherited from Attribute) |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| IsDefaultAttribute() |
When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute) |
| Match(Object) |
When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute) |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| ToString() |
Returns a string that represents the current object. (Inherited from Object) |
Explicit Interface Implementations
| _Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr) |
Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute) |
| _Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) |
Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute) |
| _Attribute.GetTypeInfoCount(UInt32) |
Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute) |
| _Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) |
Provides access to properties and methods exposed by an object. (Inherited from Attribute) |
