仅向单击的手风琴面板添加或删除类

Question

我需要一些帮助来修复手风琴组件中的一个错误：

1. 在下面的示例中，请单击面板1打开，然后再次单击面板1关闭
2. 然后单击面板2。您将看到面板1和面板2同时激活该类，这是错误的。活动类应仅添加或删除到已单击的手风琴面板

注意，我需要保持相同的功能，即手风琴面板在另一个面板打开时折叠。

非常感谢您的帮助和指导。非常感谢。

var acc = document.getElementsByClassName("accordion");
var i;
var prevExpandedPanel = null;
for (i = 0; i < acc.length; i++) {
acc[i].addEventListener("click", function() {
if (prevExpandedPanel && this !== prevExpandedPanel) {  
prevExpandedPanel.classList.toggle("active");
prevExpandedPanel.nextElementSibling.style.maxHeight = null;
}
this.classList.toggle("active");
var panel = this.nextElementSibling;
if (panel.style.maxHeight) {
panel.style.maxHeight = null;
} else {
panel.style.maxHeight = panel.scrollHeight + "px";
} 
prevExpandedPanel = this;
});
}

.accordion {
background-color: #eee;
color: #444;
cursor: pointer;
padding: 18px;
width: 100%;
border: none;
text-align: left;
outline: none;
font-size: 15px;
transition: 0.4s;
}
.active, .accordion:hover {
background-color: #f8f8f8;
}
.accordion:after {
content: '02B';
color: #777;
font-weight: bold;
float: right;
margin-left: 5px;
}
.active:after {
content: "2212";
}
.panel {
padding: 0 18px;
background-color: white;
max-height: 0;
overflow: hidden;
transition: max-height 0.2s ease-out;
}

<button class="accordion">Panel 1</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<button class="accordion">Panel 2</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<button class="accordion">Panel 3</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>

Answer 1

您混合了this的引用，但这样分配它。

试试这个：

let acc = document.querySelectorAll('.accordion');
for (let i = 0; i < acc.length; i++) {
acc[i].addEventListener("click", function() {
for (let index = 0; index < acc.length; index++) {
const el = acc[index];
if (this !== el) {
el.classList.remove('active');
el.nextElementSibling.style.maxHeight = null;
}
}
this.classList.toggle("active");
let panel = this.nextElementSibling;
if (panel.style.maxHeight) {
panel.style.maxHeight = null;
} else {
panel.style.maxHeight = panel.scrollHeight + "px";
} 
});
}

.accordion {
background-color: #eee;
color: #444;
cursor: pointer;
padding: 18px;
width: 100%;
border: none;
text-align: left;
outline: none;
font-size: 15px;
transition: 0.4s;
}
.active, .accordion:hover {
background-color: #f8f8f8;
}
.accordion:after {
content: '02B';
color: #777;
font-weight: bold;
float: right;
margin-left: 5px;
}
.active:after {
content: "2212";
}
.panel {
padding: 0 18px;
background-color: white;
max-height: 0;
overflow: hidden;
transition: max-height 0.2s ease-out;
}

<button class="accordion">Panel 1</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<button class="accordion">Panel 2</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<button class="accordion">Panel 3</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>

Answer 2

潜在的解决方案可能如下：

const accordionButtons = document.querySelectorAll(".accordion");
/* 
* create an array of object associating the `button.accordion`
* with the corresponding `div.panel`
* (this is not strictly necessary, I just find it convenient)
*/
const accordions = []
accordionButtons.forEach(button => {
accordions.push({
btnEl: button,
panelEl: button.nextElementSibling
})
});
/*
* create a function to handle the accordions toggle
*/
function expandSingle(accordion) {
const isExpanded = accordion.btnEl.classList.contains('active');

// 1. remove the active class from all accordions
//    and set the max-height of all panels to 0
accordions.forEach(item => {
item.btnEl.classList.remove('active');
item.panelEl.style.maxHeight = 0;
});

// 2. if the selected accordion was not already active/expanded
//    add the active class to it and set the max-height
if (!isExpanded) {
accordion.btnEl.classList.add('active');
accordion.panelEl.style.maxHeight = accordion.panelEl.scrollHeight + 'px';
}
}
/*
* add an event listener to each `button.accordion`, calling the function
* which handles the accordions toggle
*/
accordions.forEach(accordion => {
accordion.btnEl.addEventListener('click', () => expandSingle(accordion))
})

.accordion {
background-color: #eee;
color: #444;
cursor: pointer;
padding: 18px;
width: 100%;
border: none;
text-align: left;
outline: none;
font-size: 15px;
transition: 0.4s;
}
.active, .accordion:hover {
background-color: #f8f8f8;
}
.accordion:after {
content: '02B';
color: #777;
font-weight: bold;
float: right;
margin-left: 5px;
}
.active:after {
content: "2212";
}
.panel {
padding: 0 18px;
background-color: white;
max-height: 0;
overflow: hidden;
transition: max-height 0.2s ease-out;
}

<button class="accordion">Panel 1</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<button class="accordion">Panel 2</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<button class="accordion">Panel 3</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>

Answer 3

您需要用div:包装手风琴

<div class="accordion">
<button class="button">Panel 1</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
</div>
<div class="accordion">
<button class="button">Panel 2</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
</div>
<div class="accordion">
<button class="button">Panel 3</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
</div>

之后只需尝试以下代码：

const resetCurrentActiveAccordion = (active) => {
if(!active) return
const buttonParent = active.closest('.accordion')
const panel = buttonParent.querySelector('.panel')
active.classList.remove('active')
panel.style.maxHeight = null
}
const handleAccordionClick = event => {
const parent = event.target.closest('.accordion')
const panel = parent.querySelector('.panel')
const active = document.querySelector('.active')

resetCurrentActiveAccordion(active)
if(active === event.target) return

event.target.classList.add('active')
panel.style.maxHeight = `${panel.scrollHeight}px`;
}
const initializeAccordion = () => {
const accordions = document.querySelectorAll('.accordion')
accordions.forEach(accordion => {
const button = accordion.querySelector('.button')
const panel = accordion.querySelector('.panel')
button.addEventListener('click', handleAccordionClick)
})
}
initializeAccordion()

当然，更新你的风格：

.button {
background-color: #eee;
color: #444;
cursor: pointer;
padding: 18px;
width: 100%;
border: none;
text-align: left;
outline: none;
font-size: 15px;
transition: 0.4s;
}
.active, .button:hover {
background-color: #f8f8f8;
}
.button:after {
content: '02B';
color: #777;
font-weight: bold;
float: right;
margin-left: 5px;
}
.active:after {
content: "2212";
}
.panel {
padding: 0 18px;
background-color: white;
max-height: 0;
overflow: hidden;
transition: max-height 0.2s ease-out;
}

代码段链接：https://jsfiddle.net/j9k8hdzb/

Answer 4

您无需记住之前选择的元素即可完成此操作：

var acc = document.getElementsByClassName("accordion");
for (var i = 0; i < acc.length; i++) {
acc[i].addEventListener("click", function(e) {
let active = this.classList.contains('active');
let panel = this.nextElementSibling;

[...acc].forEach(function(item) {
item.classList.remove('active');
item.nextElementSibling.style.maxHeight = null;
});

if(!active) {
this.classList.add('active');
panel.style.maxHeight = panel.scrollHeight + "px";
}
});
}

.accordion {
background-color: #eee;
color: #444;
cursor: pointer;
padding: 18px;
width: 100%;
border: none;
text-align: left;
outline: none;
font-size: 15px;
transition: 0.4s;
}
.active, .accordion:hover {
background-color: #f8f8f8;
}
.accordion:after {
content: '02B';
color: #777;
font-weight: bold;
float: right;
margin-left: 5px;
}
.active:after {
content: "2212";
}
.panel {
padding: 0 18px;
background-color: white;
max-height: 0;
overflow: hidden;
transition: max-height 0.2s ease-out;
}

<button class="accordion">Panel 1</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<button class="accordion">Panel 2</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p><p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>
<button class="accordion">Panel 3</button>
<div class="panel">
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
</div>