Enable Navigation in a UI Automation Fragment Provider

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

See Also

Concepts

UI Automation Providers Overview
Server-Side UI Automation Provider Implementation