AutomationPropertyChangedEventArgs(AutomationProperty, Object, Object) Constructor
Definition
Important
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Initializes a new instance of the AutomationPropertyChangedEventArgs class.
public:
AutomationPropertyChangedEventArgs(System::Windows::Automation::AutomationProperty ^ property, System::Object ^ oldValue, System::Object ^ newValue);
public AutomationPropertyChangedEventArgs (System.Windows.Automation.AutomationProperty property, object oldValue, object newValue);
new System.Windows.Automation.AutomationPropertyChangedEventArgs : System.Windows.Automation.AutomationProperty * obj * obj -> System.Windows.Automation.AutomationPropertyChangedEventArgs
Public Sub New (property As AutomationProperty, oldValue As Object, newValue As Object)
Parameters
- property
- AutomationProperty
The identifier of the property that has changed.
- oldValue
- Object
The previous value of the property.
- newValue
- Object
The new value of the property.
Examples
The following example constructs and raises an event when a property has changed.
/// <summary>
/// Raises an event when the IsEnabled property on a control is changed.
/// </summary>
/// <param name="provider">The UI Automation provider for the control.</param>
/// <param name="newValue">The current enabled state.</param>
private void RaiseEnabledEvent(IRawElementProviderSimple provider, bool newValue)
{
if (AutomationInteropProvider.ClientsAreListening)
{
AutomationPropertyChangedEventArgs args =
new AutomationPropertyChangedEventArgs(AutomationElement.IsEnabledProperty,
!newValue, newValue);
AutomationInteropProvider.RaiseAutomationPropertyChangedEvent(provider, args);
}
}
''' <summary>
''' Raises an event when the IsEnabled property on a control is changed.
''' </summary>
''' <param name="provider">The UI Automation provider for the control.</param>
''' <param name="newValue">The current enabled state.</param>
Private Sub RaiseEnabledEvent(ByVal provider As IRawElementProviderSimple, ByVal newValue As Boolean)
If AutomationInteropProvider.ClientsAreListening Then
Dim args As New AutomationPropertyChangedEventArgs(AutomationElement.IsEnabledProperty, Not newValue, newValue)
AutomationInteropProvider.RaiseAutomationPropertyChangedEvent(provider, args)
End If
End Sub
Remarks
oldValue
can be null
(Nothing
in Visual Basic) if the previous value is not readily available.
Applies to
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