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Binding.UpdateSourceTrigger Property

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Gets or sets a value that determines the timing of binding source updates for two-way bindings.

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


Public Property UpdateSourceTrigger As UpdateSourceTrigger
public UpdateSourceTrigger UpdateSourceTrigger { get; set; }
<Binding UpdateSourceTrigger="updateSourceTriggerMemberName"/>

Property Value

Type: System.Windows.Data.UpdateSourceTrigger
A value that determines when the binding source is updated. The default is Default.


Exception Condition

The Binding has already been attached to a target element, and cannot be modified.


Set this property to Explicit on two-way bindings to disable automatic updates to the binding source. This is useful when you want to perform validation on binding targets before any value changes are copied to the binding source. To update the binding source, use the FrameworkElement.GetBindingExpression method to retrieve a BindingExpression for the target property, and then call the UpdateSource method.

Version Information


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0


For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.