This documentation is archived and is not being maintained.

PropertyMetadata.PropertyChangedCallback Property

Gets or sets a reference to a PropertyChangedCallback implementation specified in this metadata.

Namespace: System.Windows
Assembly: WindowsBase (in windowsbase.dll)
XML Namespace:

public PropertyChangedCallback PropertyChangedCallback { get; set; }
/** @property */
public PropertyChangedCallback get_PropertyChangedCallback ()

/** @property */
public void set_PropertyChangedCallback (PropertyChangedCallback value)

public function get PropertyChangedCallback () : PropertyChangedCallback

public function set PropertyChangedCallback (value : PropertyChangedCallback)

You cannot use this property in XAML.

Property Value

A PropertyChangedCallback implementation reference.

Exception typeCondition


Cannot set a metadata property once it is applied to a dependency property operation.

The callbacks in property metadata are not typically public members on the defining type, so the value of this property is not important for most scenarios that just consume an existing dependency property's metadata. One reason this property is exposed is so that metadata classes can perform their desired merge logic if both base metadata and overriding/adding metadata specify a PropertyChangedCallback. The default merge logic for is to maintain all PropertyChangedCallback implementations in a table and call each of them, with callbacks established by the deepest class in hierarchy running first.

PropertyChangedCallback is defined in the object model as read-write. This is so PropertyChangedCallback can be adjusted after initialization of the PropertyMetadata object itself. However, once the metadata is consumed as part of a call to Register, AddOwner, or OverrideMetadata, the property system will seal that metadata instance and the properties are now considered immutable. Attempting to set PropertyChangedCallback once IsSealed is true on this metadata instance will raise an exception.

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0