import TWEEN from 'tween.js'
// ***.vue,注意這里千萬(wàn)別在main.js中引入，否則運(yùn)行會(huì)報(bào)：TWEEN is undefined，
// 這邊存疑，不知道為什么在main.js中不執(zhí)行

<div class="sectionRight">
 <span class="numberInit" style="display:none">{{num1}}</span>
 <p class="numberGrow numberGrow1">{{formatNum1}}</p>
 <p class="sectionTxt">抵御攻擊</p>
</div>
export default {
 computed:{
 formatNum1(){
  let num = this.animatedNum1
  return (num || 0).toString().replace(/(\d)(?=(?:\d{3})+$)/g, '$1,')
 }
 },
 data () {
 return {
  num1: 0,
  animatedNum1: 0
 }
 },
 watch: {
 num1: function(newValue, oldValue) {
  var vm = this
  function animate (time) {
  requestAnimationFrame(animate)
  TWEEN.update(time)
  }
  new TWEEN.Tween({ tweeningNumber: oldValue })
  .easing(TWEEN.Easing.Quadratic.Out)
  .to({ tweeningNumber: newValue }, 5000)
  .onUpdate(function () {
   vm.animatedNum1 = this.tweeningNumber.toFixed(0) 
   //toFixed(num):num代表小數(shù)點(diǎn)后幾位
  })
  .start()
  animate()
 }
 },
 methods:{
 setAnimatedNum(){
  this.num1 = 3567892881
 },
 handleScroll(){  
  let windowH = document.body.clientHeight
  let docSrollTop = $(document).scrollTop() //文檔卷動(dòng)值
  let clientH = $(window).height() //視窗大小
  let sectionTop = $(".sectionBody").offset().top //動(dòng)態(tài)文字模塊距離文檔頭部的距離
  let sectionH = $(".sectionBody").height()
  if((docSrollTop + clientH - sectionTop) >= 0 
  && (docSrollTop - sectionTop - sectionH) <= 0){
  this.setAnimatedNum()
  }
 }
 },
 mounted(){
 this.handleScroll()
 window.addEventListener('scroll',this.handleScroll)
 }
}