gistfile1.cs

public static T FindElement<T>(this DependencyObject rootElement, string name = null)
    where T : DependencyObject
{
    var q = new Queue<DependencyObject>();
    q.Enqueue(rootElement);
    while (q.Count != 0)
    {
        var e = q.Dequeue();
        if (e is T && (name == null || !(e is FrameworkElement) || (e as FrameworkElement).Name == name)) return e as T;
        if (e == null) continue;
        var c = VisualTreeHelper.GetChildrenCount(e);
        for (var i = 0; i < c; ++i)
        {
            q.Enqueue(VisualTreeHelper.GetChild(e, i));
        }
    }
    return null;
}