AutoCompleteBox.OnDropDownOpening Method
Microsoft Silverlight will reach end of support after October 2021. Learn more.
Raises the DropDownOpening event.
Namespace: System.Windows.Controls
Assembly: System.Windows.Controls.Input (in System.Windows.Controls.Input.dll)
Syntax
'Declaration
Protected Overridable Sub OnDropDownOpening ( _
e As RoutedPropertyChangingEventArgs(Of Boolean) _
)
protected virtual void OnDropDownOpening(
RoutedPropertyChangingEventArgs<bool> e
)
Parameters
- e
Type: System.Windows.Controls.RoutedPropertyChangingEventArgs<Boolean>
A RoutedPropertyChangingEventArgs<T> that contains the event data.
Remarks
The DropDownOpening event occurs when the IsDropDownOpen property is changing from false to true.
Raising an event invokes the event handler through a delegate. The OnDropDownOpening method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.
Notes to Inheritors
When overriding OnDropDownOpening in a derived class, be sure to call the base class’s OnDropDownOpening method so that registered delegates receive the event.
Version Information
Silverlight
Supported in: 5, 4, 3
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.