Windows Dev Center

DataContextChangedEventArgs class

Provides data for the DataContextChanged event.

Inheritance

Object
  DataContextChangedEventArgs

Syntax


public sealed class DataContextChangedEventArgs

Attributes

[MarshalingBehavior(Agile)]
[Threading(Both)]
[Version(0x06030000)]
[WebHostHidden()]

Members

The DataContextChangedEventArgs class has these types of members:

Methods

The DataContextChangedEventArgs class inherits methods from the Object class.

Properties

The DataContextChangedEventArgs class has these properties.

PropertyAccess typeDescription

Handled

Read/writeGets or sets a value that influences whether another DataContextChanged event should be fired from child elements that inherit the DataContext value and detect that the value has changed.

NewValue

Read-onlyGets the new DataContext value for the element where the DataContextChanged event fired.

 

Remarks

The FrameworkElement.DataContext property has a built-in behavior whereby its value inherits to all FrameworkElement child elements of a FrameworkElement where a DataContext value is set. This behavior enables a set of related elements to use the same context to bind to different source properties, which is particularly useful for item templates, data templates, and other data binding scenarios. Because DataContext inherits, there's potential for each FrameworkElement that uses the inherited value to fire another DataContextChanged event. That event is sourced from the inheriting element, not the parent element, once the element detects that its inherited DataContext value has changed. If you don't want this behavior, you should handle the DataContextChanged event on the parent source, where the event will occur first. As part of your handler logic, set the value of the Handled property in the DataContextChangedEventArgs event data to true. That action will prevent the event from routing to child elements.

Note  DataContextChanged has routing behavior but isn't a true routed event (it does not have a RoutedEvent identifier). Also, it routes from parent to child whereas the true routed events route from child to parent. If you're familiar with Windows Presentation Foundation (WPF), DataContextChanged might be considered a tunneling routing event by the WPF event routing definitions.

Requirements (device family)

Device family

Universal

API contract

Windows.Foundation.UniversalApiContract, introduced version 1.0

Namespace

Windows.UI.Xaml
Windows::UI::Xaml [C++]

Metadata

Windows.Foundation.UniversalApiContract.winmd

Requirements (operating system)

Minimum supported client

Windows 8.1 [Windows Store apps only]

Minimum supported server

Windows Server 2012 R2 [Windows Store apps only]

Minimum supported phone

Windows Phone 8.1 [Windows Runtime apps only]

Namespace

Windows.UI.Xaml
Windows::UI::Xaml [C++]

Metadata

Windows.winmd

See also

Object
DataContextChanged
DataContext

 

 

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