预加载和懒加载

商品懒加载

核心代码

let i = 1
let loading = document.querySelector('.loading')
var ob = new IntersectionObserver(async function (entries) {
  console.log(entries[0])
  if (entries[0].isIntersecting) {
    i++
    let arr = await axios.get('/goodsdata', { params: { qty: i } })
    // console.log(arr.data)
    contentUI(arr.data)
  }

}, {
  threshold: 0.1
})
ob.observe(loading)