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错误：

1. 在下面的示例中，请单击面板 1 打开并再次单击面板 1 将其关闭。
2. 然后单击面板 2。您将看到面板 1 和面板 2 同时激活类，这是错误的。应仅将活动类添加或删除到被点击的手风琴面板中。

请注意，我需要保持相同的功能，即当另一个手风琴面板打开时折叠。

非常感谢您的帮助和指导。 谢谢。

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: '\002B';
  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

您正在混合 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: '\002B';
  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

可能的解决方案如下：

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: '\002B';
  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

你需要用 div 包裹你的手风琴：

<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，更新你的样式：

.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: '\002B';
  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sn-p链接：https://jsfiddle.net/j9k8hdzb/

Answer 4

你可以做到这一点，而不必记住之前选择的元素：

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: '\002B';
  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>