多级树形分类折叠菜单是基于jQuery实现的漂亮树形菜单代码，有2种风格。-Multilevel tree classification is based on jQuery accordion achieve a beautiful tree menu code, there are two kinds of styles.

网站后台页面左侧收缩折叠效果是基于JS技术实现的，点击小箭头，左侧列表页面就收缩折叠到一起了，代码写很精简，需要此种页面效果的朋友可以参考一下。-Website shrink back left of the page folding effect is based on the technology of JS, click on the small arrow on the left side of the page listing contraction folded together,