Enable Navigation in a UI Automation Fragment Provider
Note
This documentation is intended for .NET Framework developers who want to use the managed UI Automation classes defined in the System.Windows.Automation namespace. For the latest information about UI Automation, see Windows Automation API: UI Automation.
This topic contains example code that shows how to enable navigation in a UI Automation provider for an element that is within a fragment.
Example
The following example code implements Navigate for a list item within a list. The parent element is the list box element, and the sibling elements are other items in the list collection. The method returns null (Nothing in Visual Basic) for directions that are not valid; in this case, FirstChild and LastChild, because the element has no children.
/// <summary>
/// Navigate to adjacent elements in the automation tree.
/// </summary>
/// <param name="direction">Direction to navigate.</param>
/// <returns>The element in that direction, or null.</returns>
/// <remarks>
/// parentControl is the provider for the list box.
/// parentItems is the collection of list item providers.
/// </remarks>
public IRawElementProviderFragment Navigate(NavigateDirection direction)
{
int myIndex = parentItems.IndexOf(this);
if (direction == NavigateDirection.Parent)
{
return (IRawElementProviderFragment)parentControl;
}
else if (direction == NavigateDirection.NextSibling)
{
if (myIndex < parentItems.Count - 1)
{
return (IRawElementProviderFragment)parentItems[myIndex + 1];
}
else
{
return null;
}
}
else if (direction == NavigateDirection.PreviousSibling)
{
if (myIndex > 0)
{
return (IRawElementProviderFragment)parentItems[myIndex - 1];
}
else
{
return null;
}
}
else
{
return null;
}
}
''' <summary>
''' Navigate to adjacent elements in the automation tree.
''' </summary>
''' <param name="direction">Direction to navigate.</param>
''' <returns>The element in that direction, or null.</returns>
''' <remarks>
''' parentControl is the provider for the list box.
''' parentItems is the collection of list item providers.
''' </remarks>
Public Function Navigate(ByVal direction As NavigateDirection) As IRawElementProviderFragment _
Implements IRawElementProviderFragment.Navigate
Dim myIndex As Integer = parentItems.IndexOf(Me)
If direction = NavigateDirection.Parent Then
Return DirectCast(parentControl, IRawElementProviderFragment)
ElseIf direction = NavigateDirection.NextSibling Then
If myIndex < parentItems.Count - 1 Then
Return DirectCast(parentItems((myIndex + 1)), IRawElementProviderFragment)
Else
Return Nothing
End If
ElseIf direction = NavigateDirection.PreviousSibling Then
If myIndex > 0 Then
Return DirectCast(parentItems((myIndex - 1)), IRawElementProviderFragment)
Else
Return Nothing
End If
Else
Return Nothing
End If
End Function 'Navigate