需要使用vue做一個專題頁面。滾動頁面指定區域導航高亮。

監聽滾動頁面事件，對比當前頁面的位置與元素的位置，如果當前滾動的區域位置大于元素的位置，導航添加class，其他去掉class進行樣式切換。

我使用的方法是在定位元素上添加id，在導航添加data-id屬性，監聽滾動事件，如果當前滾動區域大于定位元素區域，將元素的id賦值給變量，然后與導航的data-id進行匹配，切換class。

html結構

main.vue

<template> <div class="qz-home">  <div class="quiz-container">   <div class="quiz-ad-pic" id="pagetop"></div>   <div class="quiz-main">    <div class="quiz-main-inside" id="js-content">     <quiz-sessions class="item" id="quizhall"></quiz-sessions>     <quizRecords class="item" id="quizrecord"></quizRecords>     <quiz-history class="item" id="quizHistory"></quiz-history>     <quiz-mine class="item" id="quizMine"></quiz-mine>     <quiz-rank class="item" id="quizRank"></quiz-rank>     <quiz-rule class="item" id="quizRule"></quiz-rule>    </div>   </div>   <navigation id="js-nav"></navigation>  </div> </div></template>

navigation.vue

<template> <nav class="nav-container">  <div class="nav-mark"></div>  <div class="nav-main">   <ul class="nav-list">    <li :class="{'cur': curindex === index}" v-for="(item, index) in navList" :key="index" :data-id="item.id"><a @click="linkTo(item.id, index)">{{item.name}}</a></li>   </ul>   <div class="backtop" @click="backTop()">    <a></a>   </div>  </div> </nav></template>

javascript

export default { name: "Navigation", data() {  return {   navList: [    { name: "競猜大廳", id: "quizhall" },    { name: "競猜記錄", id: "quizrecord" },    { name: "歷史賽事", id: "quizHistory" },    { name: "我的競猜", id: "quizMine" },    { name: "排行榜", id: "quizRank" },    { name: "玩法", id: "quizRule" }   ],   curindex: 0  }; }, mounted() {  this.initScroll(); }, methods: {  initScroll() {   window.addEventListener('scroll', function() {    // 封裝類名函數集：判斷、移除、增加、獲?。ê唵未直┌妫?   function removeClass(obj, cls) {     if (obj.className == cls) {      obj.className = "";     }    }    function addClass(obj, cls) {     if (obj.className != cls) {      obj.className = cls;     }    }    let pos = document.documentElement.scrollTop;    if (pos > 300) {     document.querySelector('.nav-container').style.display = 'block';    } else {     document.querySelector('.nav-container').style.display = 'none';    }    var menus = document.getElementById("js-nav").getElementsByTagName("li");    var items = document.getElementById("js-content").querySelectorAll(".item");    var currentId = "";        for (var i = 0; i < items.length; i++) {     var _item = items[i];     var _itemTop = _item.offsetTop;     if (pos > _itemTop - 200) {      currentId = _item.id;     } else {      break;     }    }    if (currentId) {     for (var j = 0; j < menus.length; j++) {      var _menu = menus[j];      // href屬性獲取的是整個link，需以#為界截除獲取最后一個元素；      var _href = _menu.getAttribute('data-id');      if (_href != currentId) {       removeClass(_menu, "cur");      } else {       addClass(_menu, "cur");      }     }    }   })  } }};