Vue 无限滚动加载指令实现方法

class Scroll {  static get top() {    return Math.max(document.documentElement.scrollTop || document.body.scrollTop);  }  static get clientHeight() {    return Math.max(document.documentElement.clientHeight || document.body.clientHeight);  }  static get clientWidth() {    return Math.max(document.documentElement.clientWidth || document.body.clientWidth);  }  static get height() {    return Math.max(document.documentElement.scrollHeight || document.body.scrollHeight);  }  static get width() {    return Math.max(document.documentElement.scrollWidth || document.body.scrollWidth);  }  static get bottom() {    return Scroll.height - Scroll.clientHeight - Scroll.top;  }}

const on = (function () {  if (document.addEventListener) {    return function (element, event, handler) {      if (element && event && handler) {        element.addEventListener(event, handler, false);      }    };  } else {    return function (element, event, handler) {      if (element && event && handler) {        element.attachEvent('on' + event, handler);      }    };  }})();

/** * 降低事件执行频率 */const downsampler = (function () {  let result = null;  return function (time, func) {    if (!result) {      result = setTimeout(function () {        func();        result = null;      }, time);    }  }})();Vue.directive("infinite-scroll", {  bind(el, binding, vnode) {    on(window, 'scroll', function () {      if (typeof binding.value === "function" && Scroll.bottom <= 50) {  // 小于50就触发        downsampler(50, binding.value); // 降低触发频率      }    })  }});

<div class="app" v-infinite-scroll="coupon">    <template v-for="item in goods">      <p>{{item}}</p>   </template></div>    let v = new Vue({      el: ".app",      data(){        return {          goods:[]        }      },      methods: {        coupon() {          this.goods.push("你呵呵")        }      }    })