Question

我想用JavaScript函数更改CSS类的动画属性。我一直在尝试各种方法，但没有一种方法有效。请找出我出错的地方。

CSS：

   .center {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 200px;
  height: 200px;
  border-radius: 50%;
  background: transparent;
}

.center .earth {
  position: absolute;
  top: 0;
  width: 200px;
  height: 200px;
  background-image: url(https://www.publicdomainpictures.net/pictures/90000/velka/earth-map.jpg);
  margin: 3em auto;
  border-radius: 50%;
  background-size: 630px;
  animation: spin 30s linear alternate infinite;
  box-shadow: inset 20px 0 80px 6px rgba(0, 0, 0, 1);
  color: #000;
}

.center .earth .moon {
  position: absolute;
  top: calc(50% - 1px);
  left: 50%;
  width: 200px;
  height: 2px;
  transform-origin: left;
  border-radius: 50%;
  animation: rotate 10s linear infinite;
}

.center .earth .moon::before {
  content: '';
  background-image: url(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRsvjrANMGI8aBJSFbsHteVa04rcB1IjjNsbrhm8vTLflfpiG133g);
  position: absolute;
  background-size: 200px;
  top: -25px;
  right: 0;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  animation: spin 10s linear infinite;
}

@keyframes rotate {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

@keyframes spin {
  100% {
    background-position: 100%;
  }
}

HTML：

<div className="center">
      <div className="earth">
        <div className="moon" />
      </div>
    </div>

JavaScript函数：

    function change() {
  var elem = document.getElementsByClassName('moon');
  elem.style.animation="rotate 5s linear infinite";
}

我尝试了各种方法，但没有一种能够执行修改。在这个对象中循环也没有任何帮助。

Answer 1

Vue.component('media', { template: '#media', props: ['data', 'title', 'subtitle', 'id', 'url'], data() { return { truc: 'Check me', titre: '', media: '', state: '', isInit: false, isPlay: false, duration: '' } }, methods: { test(url, event) { var $this = event.target; var self = this; self.stopOther(); if (self.isInit == false) { self.media = new Media(url, null, null, self.mediaStatus); self.isInit = true; self.media.play(); self.isPlay = true; setTimeout(() => { self.duration = self.media.getDuration(); console.log("durée : " + self.duration); self.movePlayhead(self.duration); }, 200); } else { if (self.state == 2 || self.state == 1) { self.media.pause(); self.isPlay = false; } else { self.media.play(); self.isPlay = true; console.log(self.isPlay) } } }, stopOther() { var self = this; //recuperation des autres componants media var other = self.$parent.$refs.media; for (var i = 0; i < other.length; i++) { var init = other[i].isInit; var state = other[i].state; var isPlay = other[i].isPlay; if (isPlay == true) { other[i].media.stop(); other[i].isPlay = false; console.log(other[i].isPlay); } } }, mediaStatus(status) { var self = this; //Récupère le status de la piste audio //None = 0 //Starting = 1 //Running = 2 //Pause = 3 //Stopped = 4 self.state = status; }, movePlayhead(duration) { var self = this; var position = 0; var current = 0;; $(".timeline").slider({ min: 0, max: self.duration, orientation: "horizontal", slide: function (event, ui) { self.media.seekTo(ui.value * 1000); //en millisecondes } }) requestAnimationFrame(self.step); }, step() { var self = this; var anim self.media.getCurrentPosition(function (position) { if (position > -1 && self.isPlay == true) { position = position; current = position; $(".timeline").slider('value', current); } if (position === self.duration || self.isPlay == false) { //$(".song .control-btn i").removeClass("icon-network").addClass("icon-play"); cancelAnimationFrame(anim) } }); anim = requestAnimationFrame(self.step); } } });是元素的HTMLCollection，而不是单个元素，并且设置HTMLCollection的<script type="text/javascript" src="lib/pouchDB/pouchdb.js"></script> <script type="text/javascript" src="lib/pouchDB/pouchdb-find.js"></script> <script type="text/javascript" src="lib/pouchdb-adapt/pouchdb.cordova-sqlite.js"></script> <script type="text/javascript" src="lib/vuejs/vuejs.js"></script> <script type="text/javascript" src="scripts/script.js"></script>属性不起作用。

相反，您希望单独更改每个元素的样式：

elem

修改

这是一个片段，表明该方法有效/提供参考：

＆＃13;
＆＃13;
style
＆＃13;
Array.from(document.getElementsByClassName('moon')).forEach(elem => { elem.style.animationDuration = "5s"; });
＆＃13;
function change_spin_rate() { Array.from(document.getElementsByClassName('spinner')).forEach(elem => { elem.style.animationDuration = "1s"; }); } document.getElementById("spin_change").onclick = change_spin_rate;
＆＃13;
＆＃13;
＆＃13;

Answer 2

试试这个：

function change() {
  let elems = document.getElementsByClassName("moon");
  elems.forEach(elem => elem.style.animation = "rotate 5s linear infinite");
}

Answer 3

document.getElementsByClassName返回多个元素。您需要遍历它们并将更改应用于每个元素。

function change() {
  Array.from(document.getElementsByClassName("moon")).forEach((elem) => {
    elem.style.animation = "rotate 5s linear infinite";
  });
}

document.getElementsByClassName不会返回数组。您必须先使用Array.from才能拨打Array.prototype.forEach。

顺便说一下，除非您正在编写React JSX，否则<div className="moon" />应为<div class="moon" />。

使用JavaScript更改带有classname的div的CSS

3 个答案: