Export (0) Print
Expand All
This topic has not yet been rated - Rate this topic

IViewAutomationPeer Interface

Allows a customized view of a ListView that derives from ViewBase to implement automation peer features that are specific to the custom view.

Namespace:  System.Windows.Automation.Peers
Assembly:  PresentationFramework (in PresentationFramework.dll)
'Declaration
Public Interface IViewAutomationPeer

The IViewAutomationPeer type exposes the following members.

  NameDescription
Public methodCreateItemAutomationPeerCreates a new instance of the ItemAutomationPeer class.
Public methodGetAutomationControlTypeGets the control type for the element that is associated with this IViewAutomationPeer.
Public methodGetChildrenGets the collection of immediate child elements of the specified UI Automation peer.
Public methodGetPatternGets the control pattern that is associated with the specified patternInterface.
Public methodItemsChangedCalled by ListView when the collection of items changes.
Public methodViewDetachedCalled when the custom view is no longer applied to the ListView.
Top

The following code shows a custom view implementing IViewAutomationPeer in a separate class to handle a button that appears at the top of the ListView control.

	Public Class OneButtonHeaderView
		Inherits ViewBase
		Protected Overrides Function GetAutomationPeer(ByVal parent As ListView) As IViewAutomationPeer
			Return New OneButtonHeaderViewAutomationPeer(Me, parent)
		End Function


...


	Public Class OneButtonHeaderViewAutomationPeer
		Implements IViewAutomationPeer
		Private m_lv As ListView

		Public Sub New(ByVal control As OneButtonHeaderView, ByVal parent As ListView)
			m_lv = parent
		End Sub

		Private Function CreateItemAutomationPeer(ByVal item As Object) As ItemAutomationPeer Implements IViewAutomationPeer.CreateItemAutomationPeer
			Dim lvAP As ListViewAutomationPeer = TryCast(UIElementAutomationPeer.FromElement(m_lv), ListViewAutomationPeer)
			Return New ListBoxItemAutomationPeer(item, lvAP)
		End Function

		Private Function GetAutomationControlType() As AutomationControlType Implements IViewAutomationPeer.GetAutomationControlType
			Return AutomationControlType.List
		End Function

		Private Function GetChildren(ByVal children As List(Of AutomationPeer)) As List(Of AutomationPeer) Implements IViewAutomationPeer.GetChildren
			' the children parameter is a list of automation peers for all the known items
			' our view must add its banner button peer to this list.

			Dim b As Button = CType(m_lv.Template.FindName("BannerButton", m_lv), Button)
			Dim peer As AutomationPeer = UIElementAutomationPeer.CreatePeerForElement(b)

			'If children is null, we still need to create an empty list to insert the button
			If children Is Nothing Then
				children = New List(Of AutomationPeer)()
			End If

			children.Insert(0, peer)

			Return children
		End Function

		Private Function GetPattern(ByVal patternInterface As PatternInterface) As Object Implements IViewAutomationPeer.GetPattern
			' we can invoke the banner button 
			If patternInterface = PatternInterface.Invoke Then
				Dim b As Button = CType(m_lv.Template.FindName("BannerButton", m_lv), Button)
				Dim peer As AutomationPeer = UIElementAutomationPeer.FromElement(b)
				If peer IsNot Nothing Then
					Return peer
				End If
			End If

			' if this view does not have special handling for the pattern interface, return null
			' the ListViewAutomationPeer.GetPattern default handling will be used.
			Return Nothing
		End Function

		Private Sub ItemsChanged(ByVal e As System.Collections.Specialized.NotifyCollectionChangedEventArgs) Implements IViewAutomationPeer.ItemsChanged
		End Sub

		Private Sub ViewDetached() Implements IViewAutomationPeer.ViewDetached
		End Sub
	End Class

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Did you find this helpful?
(1500 characters remaining)
Thank you for your feedback
Show:
© 2014 Microsoft. All rights reserved.