https://www.shizeyuan.com/i/js2/m_menu/m_menu_01.js

1/*原生*/ 
2const body = document.body;
3const _top = 0;
4
5var isTouch = !!('ontouchstart' in document.documentElement) || !!('onmsgesturestart' in document.documentElement);
6var events = {click: 'click',fastClick: isTouch ? 'touchend' : 'click'};
7
8
9document.getElementById("m_menu").addEventListener(events.fastClick,function(e){ 
10  document.querySelector(".nav_panel").classList.add("open");
11},false);
12
13
14var m_menu_close = document.getElementById("m_menu_close");
15if(m_menu_close){
16  document.getElementById("m_menu_close").addEventListener(events.fastClick,function(e){ 
17    document.querySelector(".nav_panel").classList.remove("open");  //删
18    body.classList.remove('off_canvas_active'); //删除一个半透明遮罩
19  },false);
20}
21
22var m_panel = document.getElementById("m_panel");
23if(m_panel){
24document.getElementById("m_panel").addEventListener(events.fastClick,function(e){ 
25  document.querySelector(".more_panel").classList.add("open");
26  body.classList.add('off_canvas_active');
27  
28},false);
29}
30
31var m_panel_close = document.getElementById("m_panel_close");
32if(m_panel_close){
33  document.getElementById("m_panel_close").addEventListener(events.fastClick,function(e){ 
34    document.querySelector(".more_panel").classList.remove("open");
35    body.classList.remove('off_canvas_active');
36  },false);
37}
38
39function sticky(){
40  var sticky_wrapper = document.getElementById("sticky_wrapper");
41  var stickydata = document.getElementById("sticky_nav");
42  
43  var stickytop = stickydata.offsetTop;
44  var stickyhei = stickydata.offsetHeight;
45 
46
47  window.onscroll = function(){ 
48    var t=document.documentElement.scrollTop||document.body.scrollTop; 
49    if(window.innerWidth < 992){
50      if(t >= stickyhei){ 
51        stickydata.classList.add("head_sticky");
52        sticky_wrapper.style.height = stickyhei + 'px';
53      }else{
54        stickydata.classList.remove("head_sticky");
55        sticky_wrapper.style.height = 'auto';
56      } 
57    }else{
58      if(t >= stickytop){ 
59	  
60        if(stickydata.classList.contains("sticky-transparent") == false){
61          sticky_wrapper.style.height = stickyhei + 'px';
62        }
63        stickydata.classList.add("head_sticky");
64      }else{
65        stickydata.classList.remove("head_sticky");
66        sticky_wrapper.style.height = 'auto';
67      } 
68    }
69  }
70 
71};
72sticky();
73
74var dropdown_toggle=document.querySelector(".dropdown_toggle");
75if(dropdown_toggle){
76document.querySelector(".dropdown_toggle").addEventListener(events.fastClick,function(e){ 
77   this.classList.toggle("open"); 
78},false);
79}
80
81
82var m_menu = body.querySelector(".m_menu");
83var dropdown_plus = m_menu.querySelectorAll(".dropdown-plus");
84if(dropdown_plus){
85  dropdown_plus.forEach((item) => {
86      item.addEventListener(events.fastClick,function(e){
87      item.parentNode.classList.toggle("open");
88      });
89  });
90}