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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)

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.
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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 : ViewBase
{
    protected override IViewAutomationPeer GetAutomationPeer(ListView parent)
    {
        return new OneButtonHeaderViewAutomationPeer( this, parent );
    }


...


public class OneButtonHeaderViewAutomationPeer : IViewAutomationPeer
{
    ListView m_lv;

    public OneButtonHeaderViewAutomationPeer(OneButtonHeaderView control, ListView parent)
    {
        m_lv = parent;
    }

    ItemAutomationPeer IViewAutomationPeer.CreateItemAutomationPeer(Object item)
    {
        ListViewAutomationPeer lvAP = UIElementAutomationPeer.FromElement(m_lv) as ListViewAutomationPeer;
        return new ListBoxItemAutomationPeer(item, lvAP);
    }

    AutomationControlType IViewAutomationPeer.GetAutomationControlType()
    {
        return AutomationControlType.List;
    }

    List<AutomationPeer> IViewAutomationPeer.GetChildren(List<AutomationPeer> children)
    {
        // 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.

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

        //If children is null, we still need to create an empty list to insert the button 
        if (children == null)
        {
            children = new List<AutomationPeer>();
        }

        children.Insert(0, peer);

        return children;
    }

    Object IViewAutomationPeer.GetPattern(PatternInterface patternInterface)
    {
        // we can invoke the banner button  
        if (patternInterface == PatternInterface.Invoke)
        {
            Button b = (Button)m_lv.Template.FindName("BannerButton", m_lv);
            AutomationPeer peer = UIElementAutomationPeer.FromElement(b);
            if (peer != null)
                return peer;
        }

        // if this view does not have special handling for the pattern interface, return null 
        // the ListViewAutomationPeer.GetPattern default handling will be used. 
        return null;
    }

    void IViewAutomationPeer.ItemsChanged(System.Collections.Specialized.NotifyCollectionChangedEventArgs e) { }

    void IViewAutomationPeer.ViewDetached() { }
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

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.

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