Represents an object that participates in the dependency property system.
Assembly: WindowsBase (in WindowsBase.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
Thetype exposes the following members.
|DependencyObjectType||Gets the DependencyObjectType that wraps the CLR type of this instance.|
|Dispatcher||Gets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.)|
|IsSealed||Gets a value that indicates whether this instance is currently sealed (read-only).|
|CheckAccess||Determines whether the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.)|
|ClearValue(DependencyProperty)||Clears the local value of a property. The property to be cleared is specified by a DependencyProperty identifier.|
|ClearValue(DependencyPropertyKey)||Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey.|
|CoerceValue||Coerces the value of the specified dependency property. This is accomplished by invoking any CoerceValueCallback function specified in property metadata for the dependency property as it exists on the calling .|
|Equals||Determines whether a provided is equivalent to the current . (Overrides Object.Equals(Object).)|
|Finalize||Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)|
|GetHashCode||Gets a hash code for this . (Overrides Object.GetHashCode.)|
|GetLocalValueEnumerator||Creates a specialized enumerator for determining which dependency properties have locally set values on this .|
|GetType||Gets the Type of the current instance. (Inherited from Object.)|
|GetValue||Returns the current effective value of a dependency property on this instance of a .|
|InvalidateProperty||Re-evaluates the effective value for the specified dependency property|
|MemberwiseClone||Creates a shallow copy of the current Object. (Inherited from Object.)|
|OnPropertyChanged||Invoked whenever the effective value of any dependency property on this has been updated. The specific dependency property that changed is reported in the event data.|
|ReadLocalValue||Returns the local value of a dependency property, if it exists.|
|SetCurrentValue||Sets the value of a dependency property without changing its value source.|
|SetValue(DependencyProperty, Object)||Sets the local value of a dependency property, specified by its dependency property identifier.|
|SetValue(DependencyPropertyKey, Object)||Sets the local value of a read-only dependency property, specified by the DependencyPropertyKey identifier of the dependency property.|
|ShouldSerializeProperty||Returns a value that indicates whether serialization processes should serialize the value for the provided dependency property.|
|ToString||Returns a string that represents the current object. (Inherited from Object.)|
|VerifyAccess||Enforces that the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.)|
The class enables Windows Presentation Foundation (WPF) property system services on its many derived classes.
The property system's primary function is to compute the values of properties, and to provide system notification about values that have changed. Another key class that participates in the property system is DependencyProperty. DependencyProperty enables the registration of dependency properties into the property system, and provides identification and information about each dependency property, whereas as a base class enables objects to use the dependency properties.
services and characteristics include the following:
Dependency property hosting support. You register a dependency property by calling the Register method, and storing the method's return value as a public static field in your class.
Attached property hosting support. You register an attached property by calling the RegisterAttached method, and storing the method's return value as a public static read-only field in your class. (There are also additional member requirements; note that this represents a WPF specific implementation for attached properties. For details, see Attached Properties Overview.) Your attached property can then be set on any class that derives from .
Get, set, and clear utility methods for values of any dependency properties that exist on the .
Metadata, coerce value support, property changed notification, and override callbacks for dependency properties or attached properties. Also, the class facilitates the per-owner property metadata for a dependency property.
The following example derives from to create a new abstract class. The class then registers an attached property and includes support members for that attached property.
Public MustInherit Class AquariumObject3 Inherits DependencyObject Public Enum Bouyancy Floats Sinks Drifts End Enum Public Shared ReadOnly BouyancyProperty As DependencyProperty = DependencyProperty.RegisterAttached("Bouyancy", GetType(Bouyancy), GetType(AquariumObject3), New FrameworkPropertyMetadata(Bouyancy.Floats, FrameworkPropertyMetadataOptions.AffectsArrange), New ValidateValueCallback(AddressOf ValidateBouyancy)) Public Shared Sub SetBouyancy(ByVal element As UIElement, ByVal value As Bouyancy) element.SetValue(BouyancyProperty, value) End Sub Public Shared Function GetBouyancy(ByVal element As UIElement) As Bouyancy Return CType(element.GetValue(BouyancyProperty), Bouyancy) End Function Private Shared Function ValidateBouyancy(ByVal value As Object) As Boolean Dim bTest As Bouyancy = CType(value, Bouyancy) Return (bTest = Bouyancy.Floats OrElse bTest = Bouyancy.Drifts OrElse bTest = Bouyancy.Sinks) End Function Public Shared ReadOnly IsDirtyProperty As DependencyProperty = DependencyProperty.Register("IsDirty", GetType(Boolean), GetType(AquariumObject3)) End Class
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.