Extensions method that searches up or down VisualTree from the source element

WinRTXamlQueryExtensions.cs

public static class WinRTXamlQuery
{
    /// <summary>
    /// Searches descendants recursively down to the last one
    /// </summary>
    /// <typeparam name="T">FrameworkElement type expected</typeparam>
    /// <param name="Source">FrameworkElement searched from</param>
    /// <param name="Name">Name of the control to expect</param>
    public static IEnumerable<T> GetDescendents<T>(this FrameworkElement Source, string Name = "")
    {
        for (int i = 0; i < VisualTreeHelper.GetChildrenCount(Source); i++)
        {
            var child = VisualTreeHelper.GetChild(Source, i);

            if (child != null)
            {
                if (Name == "")
                {
                    if (child.GetType() == typeof(T))
                    {
                        yield return (T)Convert.ChangeType(child, typeof(T));
                    }
                }
                else
                {
                    FrameworkElement fc = child as FrameworkElement;
                    if (child.GetType() == typeof(T) && fc.Name == Name)
                    {
                        yield return (T)Convert.ChangeType(child, typeof(T));
                    }
                }

                foreach (T childOfChild in GetDescendents<T>((FrameworkElement)child, Name))
                {
                    yield return childOfChild;
                } 
            }
        }
    }


    /// <summary>
    /// Searches ascendants recursively up to the first one
    /// </summary>
    /// <typeparam name="T">FrameworkElement type expected</typeparam>
    /// <param name="Source">FrameworkElement searched from</param>
    /// <param name="Name">Name of the control to expect</param>
    public static IEnumerable<T> GetAscendants<T>(this FrameworkElement Source, string Name = "")
    {
        var parent = VisualTreeHelper.GetParent(Source);

        if (parent != null)
        {
            if (Name == "")
            {
                if (parent.GetType() == typeof(T))
                {
                    yield return (T)Convert.ChangeType(parent, typeof(T));
                }
            }
            else
            {
                var fc = parent as FrameworkElement;
                if (parent.GetType() == typeof(T) && fc.Name == Name)
                {
                    yield return (T)Convert.ChangeType(parent, typeof(T));
                }
            }

            foreach (var p in GetAscendants<T>((FrameworkElement)parent))
            {
                yield return p;
            }
        }            
    }
}