OnPropertyChanged Method

FrameworkContentElement.OnPropertyChanged Method (DependencyPropertyChangedEventArgs)


Invoked whenever the effective value of any on this FrameworkContentElement has been updated. The specific dependency property that changed is reported in the arguments parameter. Overrides OnPropertyChanged.GTMT

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

protected override void OnPropertyChanged(
	DependencyPropertyChangedEventArgs e


Type: System.Windows.DependencyPropertyChangedEventArgs

The event data that describes the property that changed, including the old and new values.

This method is not intended to generally detect property changes or invalidations. It is instead intended for modifications of the general invalidation pattern if certain information is known about wide classifications of properties.

This method is potentially invoked many times during the life of an object. Therefore, you can achieve better performance if you override the metadata of specific properties and then attach CoerceValueCallback or PropertyChangedCallback functions for individual properties. However, you would use this method if a FrameworkContentElement includes a significant number of value-interrelated dependency properties, or if it includes logic such as rendering behavior that must be rerun for several related cases of property invalidations.

Note that there is an identically named OnPropertyChanged method with a different signature (the parameter type is PropertyChangedEventArgs) that can appear on a number of classes. That OnPropertyChanged is used for data object notifications, and is part of the contract for INotifyPropertyChanged.

Notes to Inheritors:

Always call the base implementation, as the first operation in your implementation. Failure to do this will significantly disable the entire WPF property system, which causes incorrect values to be reported.

.NET Framework
Available since 3.0
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