silverlight遍历子元素 Get Descendant ,Childern

项目中遇到需要获取一个元素的所有子元素或后代元素， 系统有FindName("Name"),但我们需要的元素大部分都没有name,而且FindName只能返回一个结果。我们扩展了  方法，解决的获取所有子元素或后代元素

       public static List<DependencyObject> GetChildern(this DependencyObject root)
        {
            if (root == null)
                return null;
            int count = VisualTreeHelper.GetChildrenCount(root);
            if (count <= 0)
                return null;
            List<DependencyObject> child = new List<DependencyObject>();
            for (int i = 0; i < count; i++)
            {
                DependencyObject c = VisualTreeHelper.GetChild(root, i);
                if (c != null)
                    child.Add(c);
            }
            return child;
        }

        public static List<DependencyObject> GetDescendants(this DependencyObject root)
        {
            if (root == null)
                return null;
            List<DependencyObject> temp = root.GetChildern();
            if (temp == null || temp.Count == 0)
                return null;
            List<DependencyObject> ds = new List<DependencyObject>();          
            ds.AddRange(temp);
            foreach (var t in temp)
            {
                List<DependencyObject> list = t.GetDescendants();
                if (list != null && list.Count > 0)
                    ds.AddRange(list);
            }
            return ds;          
        }