Javascript CSS手风琴转换不工作

我有一个手风琴设置，除了过渡效果外，似乎工作良好。假设触发效果的两个更改是通过JavaScript更改类时的最大宽度和不透明度

当我使用Chrome的开发工具时，如果我手动更改“max width”，效果将按照预期的方式发生，所以我有点困惑

HTML

JavaScript

// accordian toggle
var acc = document.getElementsByClassName("accordion");
var panel = document.getElementsByClassName('panel');

for (var i = 0; i < acc.length; i++) {
    acc[i].onclick = function() {
        var setClasses = !this.classList.contains('active');
        setClass(acc, 'active', 'remove');
        setClass(panel, 'show', 'remove');

        if (setClasses) {
            this.classList.toggle("active");
            this.nextElementSibling.classList.toggle("show");
        }
    }
}

function setClass(els, className, fnName) {
    for (var i = 0; i < els.length; i++) {
        els[i].classList[fnName](className);
    }
}

//手风琴式切换
var acc=document.getElementsByClassName（“accordion”）；
var panel=document.getElementsByClassName（'panel'）；
对于（变量i=0；i

提前谢谢

你就快到了

为了让这个带有“最大高度”的动画技巧发挥作用，您只需添加

max height:0

到

面板

类

原因如下：这样，它将从

max height:0

开始动画，并将动画设置为您设置的最大高度-在您的示例中：

max height:500px或任何你喜欢的，只要它超过内容的高度（在所有屏幕尺寸上）。如果不将“最大高度”设置为0，默认值为
none
，浏览器无法从
none
设置动画到
500px
。这就是它的工作方式

这里有一把小提琴给你：
非常感谢！看着你的小提琴，我才意识到我有.panel和.panel.show各两次，这就是问题的根源。我很高兴这解决了你的问题@凯夫蒙，我可以请你接受我的回答吗？
/* accordian */
button.accordion {
  font-family: 'Kulturista Bold Italic', Sans-Serif;
  background-color: #f1f1f1;
  color: $TTMdarkBlue;
  cursor: pointer;
  padding: 18px;
  width: 100%;
  text-align: left;
  border: none;
  border-radius: 0;
  outline: none;
  transition: 0.4s;
}
button:first-of-type {border-radius: 8px 8px 0 0;}
button:last-of-type {border-radius:  0 0 10px 10px;}
button.accordion.active, button.accordion:hover {
  background-color: $TTMdarkBlue;
  color: white;
}
.panel {
  padding: 0 18px;
  background-color: white;
  display: none;
}
.panel.show {
  display: block;
}
.panel {
  padding: 18px 18px;
  background-color: white;
  max-height: 0;
  overflow: hidden;
  transition: all 0.6s ease-in-out;
  opacity: 0;
}
.panel.show {
  opacity: 1;
  max-height: 500px; /* Whatever you like, as long as its more than the height of the content (on all screen sizes) */
}
.panel:last-of-type {
  border-radius: 0 0 10px 10px;
}
.accordian-section {
  // height: 283px;
}
button.accordion:after {
  content: '+'; /* Unicode character for "plus" sign (+) */
  color: $TTMdarkBlue;
  float: right;
  margin-left: 5px;
}
button.accordion:hover:after {
  color: white;
}
button.accordion.active:after {
  content: "-"; /* Unicode character for "minus" sign (-) */
  color: white !important;
}
.image-container, .description-container {
  float: left;
  width: 50%;
  box-sizing: border-box;
}
.description-container {
  padding-left: 5px;
}
.includes {margin-bottom: 0;}
.select-button {float:right;}
.btn {
  color: white;
  font-family: 'Kulturista Bold Italic', Sans-Serif;
  background-color: $TTMmediumOrange;
  padding: 9px;
  margin-bottom: 10px;
  width: 130px;
  font-size: 20px;
  text-align: center;
  text-transform: uppercase;
  border-radius: 3px;
  transition: all 0.1s;
  cursor: pointer;
}
.btn:hover {
  background-color: $TTMlightOrange;
}
table {
  border-collapse: collapse;
  width: 100%;
}
tr {
  font-size: 12px !important;
}
td, th {
  border: 1px solid #dfdfdf;
  text-align: left;
  padding: 2px 4px;
}
tr:nth-child(even) {
  background-color: #dfdfdf;
}

/* end accordian */

// accordian toggle
var acc = document.getElementsByClassName("accordion");
var panel = document.getElementsByClassName('panel');

for (var i = 0; i < acc.length; i++) {
    acc[i].onclick = function() {
        var setClasses = !this.classList.contains('active');
        setClass(acc, 'active', 'remove');
        setClass(panel, 'show', 'remove');

        if (setClasses) {
            this.classList.toggle("active");
            this.nextElementSibling.classList.toggle("show");
        }
    }
}

function setClass(els, className, fnName) {
    for (var i = 0; i < els.length; i++) {
        els[i].classList[fnName](className);
    }
}