wpf 寻找某个控件下的子控件

/// <summary>

        /// 寻找某个控件下的子控件

        /// </summary>

        /// <typeparam name="ChildType"></typeparam>

        /// <param name="obj"></param>

        /// <returns></returns>

        private ChildType FindVisualChild<ChildType>(DependencyObject obj) where ChildType : DependencyObject

        {

            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)

            {

                DependencyObject child = VisualTreeHelper.GetChild(obj,i);

                if (child!=null&& child is ChildType)

                {

                    return child as ChildType;

                }

                else

                {

                    ChildType childOfChildren = FindVisualChild<ChildType>(child);

                    if (childOfChildren!=null)

                    {

                        return childOfChildren;

                    }

                }

            }

            return null;

        }