FrameworkPropertyMetadata.Merge Method (PropertyMetadata, DependencyProperty)


The .NET API Reference documentation has a new home. Visit the .NET API Browser on to see the new experience.

Enables a merge of the source metadata with base metadata.

Namespace:   System.Windows
Assembly:  PresentationFramework (in PresentationFramework.dll)

protected override void Merge(
	PropertyMetadata baseMetadata,
	DependencyProperty dp


Type: System.Windows.PropertyMetadata

The base metadata to merge.

Type: System.Windows.DependencyProperty

The dependency property this metadata is being applied to.

This method is used internally when metadata is being overridden.

Notes to Inheritors:

Classes that derive from PropertyMetadata (or this class particularly) should override this method to account for any metadata properties they have added in their implementations. For instance, your implementation might have added a new flagwise enumeration value, and the Merge implementation should then be able to combine those flags correctly.

Always call the base implementation prior to your own implementation, because the base implementation takes care of merging all the properties already defined on previous types in the hierarchy.

The behavior added by the Merge implementation in FrameworkPropertyMetadata is that specific WPF framework-level properties in the metadata such as AffectsRender are combined in a bitwise or operation.

The Merge behavior also implements the behavior when you override the property metadata on an existing dependency property by calling OverrideMetadata., using override metadata that is FrameworkPropertyMetadata.

.NET Framework
Available since 3.0
Return to top