delegate Rectangle MyDelegate(Rectangle clientRect);

/// <summary>
/// Gets the child element that is at the specified point.
/// </summary>
/// <param name="x">Distance from the left of the application window.</param>
/// <param name="y">Distance from the top of the application window.</param>
/// <returns>The provider for the element at that point.</returns>
IRawElementProviderFragment IRawElementProviderFragmentRoot.ElementProviderFromPoint(
    double x, double y)
{
    // The RectangleToScreen method on the control can't be called directly from 
    // this thread, so use delegation.
    MyDelegate del = new MyDelegate(this.RectangleToScreen);
    Rectangle screenRectangle = (Rectangle)this.Invoke(del, new object[] { this.DisplayRectangle });

    if (screenRectangle.Contains((int)x, (int)y))
    {
        int index = (int)(((int)(y - screenRectangle.Y)) / itemHeight);
        if (index < myItems.Count)
        {
            return (IRawElementProviderFragment)myItems[index];
        }
        else
        {
            return (IRawElementProviderFragment)this;
        }
    }
    else
    {
        return null;
    }
}