DependencyObject.ClearValue Method (DependencyPropertyKey)
Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey.
Assembly: WindowsBase (in WindowsBase.dll)
A DependencyPropertyKey identifies a read-only dependency property for property system operations. Classes that define read-only dependency properties should not expose this key with public access. A publicly exposed key would provide a public code pathway that negated the read-only character of the property, if methods such as ClearValue or SetValue could be called outside the class or assembly, referencing the key.
Clearing the property value by calling ClearValue does not necessarily give a dependency property the default value that is specified in the dependency property metadata. Clearing the value only specifically clears whatever local value may have been applied. For more information, see Dependency Property Value Precedence.