var scroll = document.documentElement.scrollTop || document.body.scrollTop; //獲取屏幕距離頂部的距離

init:function(){  doc.addEventListener("scroll",function(){ // 實時監聽，如果是ios需要做300ms延遲，否則點擊索引的時候，對象距離頂部的高度不夠，會出現閃動的效果，體驗感不佳    if(!noScroll){      var appealDo = vm.$el.querySelector("#appealDo").offsetTop- 45; //獲取#appealDo距離頂部的距離      var appealComm = vm.$el.querySelector("#appealComm").offsetTop- 45; //獲取#appealComm距離頂部的距離      var scrollTop = doc.body.scrollTop || doc.documentElement.scrollTop; //獲取屏幕距離頂部的距離      if(scrollTop <= appealDo){        vm.activeIdx = 0; // activeIdx 是表示高亮，用作頂欄菜單      }else if(scrollTop > appealDo && scrollTop <= appealComm){        vm.activeIdx = 1;      }else if(scrollTop > appealComm){        vm.activeIdx = 2;      }    }    noScroll = false;  });},toggleTypes:function(idx){  noScroll = true;  if (vm.activeIdx != idx) {    if (idx === 0) {      doc.body.scrollTop = 0;      doc.documentElement.scrollTop = 0;    }else if(idx === 1){      vm.$nextTick(function(){        doTop = vm.$el.querySelector("#appealDo").offsetTop - 45;        doc.body.scrollTop = doTop;        doc.documentElement.scrollTop = doTop;      });    }else{      vm.$nextTick(function(){        doTop = vm.$el.querySelector("#appealComm").offsetTop - 45;        doc.body.scrollTop = doTop;        doc.documentElement.scrollTop = doTop;      });    }    vm.activeIdx = idx;  }},

mounted() {  window.addEventListener('scroll', this.menu)},methods: {  menu() {    this.scroll = document.documentElement.scrollTop || document.body.scrollTop;    var opacity = this.scroll / 44;    if (opacity <= 1) {      this.$nextTick(() => {        this.opacity = opacity      });    } else {      this.opacity = 1    }  } }