ValuePattern.SetValue Throws ElementNotAvailableException (Inner Exception of InvalidOperationException)

Question

I have a Wpf FrameworkElement derived control that offers a custom AutomationPeer:
using System;
using System.Collections.Generic;
using System.Text;
using System.Windows;
using System.Windows.Automation.Peers;
using System.Windows.Automation.Provider;
namespace TSystem.Content
internal class MarkTopicElementAutomationPeer : FrameworkElementAutomationPeer, IValueProvider
private static readonly Dictionary<string, TcsMarkStates> StringToStateMap = new Dictionary
<string, TcsMarkStates>
{"Positive", TcsMarkStates.Positive},
{"Negative", TcsMarkStates.Negative},
{"Neutral", TcsMarkStates.Neutral}
#region Constructors
public MarkTopicElementAutomationPeer(FrameworkElement owner) : base(owner)
if (!(owner is MarkTopicElement))
throw new ArgumentException("Owner must derive from MarkTopicElement");
#endregion
#region Automation Peer Overrides
protected override string GetNameCore()
StringBuilder name = new StringBuilder();
name.AppendFormat("MarkTopicElement:{0}:{1}", OwnerAsElement.Caption, OwnerAsElement.ElementID);
Topic parentTopic = OwnerAsElement.FindLogicalAncestorByType<Topic>();
if (null != parentTopic)
name.AppendFormat(":ParentTopic:{0}:{1}", parentTopic.GetType(), parentTopic.Instance);
return name.ToString();
public override object GetPattern(PatternInterface patternInterface)
return patternInterface == PatternInterface.Value ? this : base.GetPattern(patternInterface);
protected override AutomationControlType GetAutomationControlTypeCore()
return AutomationControlType.ComboBox;
protected override bool IsContentElementCore()
return true;
protected override bool IsControlElementCore()
return true;
#endregion
#region IValueProvider Implementation
public bool IsReadOnly
get { return OwnerAsElement.ReadOnly; }
public void SetValue(string value)
OwnerAsElement.ChangeMarkState(StateFromString(value));
public string Value
get { return OwnerAsElement.MarkState.ToString(); }
#endregion
#region Helper methods
private MarkTopicElement OwnerAsElement
get { return (MarkTopicElement) Owner; }
private static TcsMarkStates StateFromString(string value)
TcsMarkStates state;
return (StringToStateMap.TryGetValue(value, out state) ? state : TcsMarkStates.Neutral);
#endregion
However, when I try to access its implementation the ValuePattern:
WpfComboBox mark = HistoryPage.UIEVSite234Window.UIHostedPageWindow.UIItemCustom.UIItemCustom11.StartedTopic.StartedJustPTA;
var markElement = (AutomationElement) mark.NativeElement;
ValuePattern pattern = (ValuePattern) markElement.GetCurrentPattern(ValuePattern.Pattern);
pattern.SetValue("Positive");
It throws this exception:
Result Message: 
Test method EVTCSTest.HistoryStartedTest.SetStartedToPositive threw exception:
System.Windows.Automation.ElementNotAvailableException: Element not available ---> System.InvalidOperationException: Operation is not valid due to the current state of the object.
Result StackTrace: 
at UIAutomationClient.IUIAutomationValuePattern.SetValue(String val)
   at System.Windows.Automation.ValuePattern.SetValue(String value)
 --- End of inner exception stack trace ---
    at System.Windows.Automation.ValuePattern.SetValue(String value)
   at EVTCSTest.HistoryStartedTest.SetStartedToPositive() in c:\Development\zTest\EVTCSTest\EVTCSTest\HistoryStartedTest.cs:line 46
Any ideas why this may be?  I know that the element is enabled and is not read only.
One final update...I have confirmed that it is getting to my implementation of the read-only Value property of my automation peer.  However it doesn't seem to even be reaching my implementation of SetValue.
Thanks,
Kelly Hilliard

Answer 1

Hi,
Based on your description, I don’t think that the issue is really related to Coded UI test itself. Your issue is mainly on setting a value using ValuePattern.SetValue. I think it is more related to accessibility and automation. I noticed that you post a
new thread on Windows Desktop Development for Accessibility and automation forum:
http://social.msdn.microsoft.com/Forums/windowsdesktop/en-US/8c8f4566-22df-4944-ba57-13898dcec6be/valuepatternsetvalue-throws-elementnotavailableexception-inner-exception-of?forum=windowsaccessibilityandautomation#8c8f4566-22df-4944-ba57-13898dcec6be
I am not an expert on accessibility and automation, I am sorry for that I can’t provide you something useful about ValuePattern.SetValue method’s usage. I think that community members on Windows Desktop Development for Accessibility and Automation forum
will help you resolve this issue better.
Thank you for your understanding and support.
Best regards,
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