Question

使用 Javascript 打开手风琴

2017-02-21

540

javascript accordion

我在我的网站上分离了这个手风琴

https://www.w3schools.com/howto/howto_js_accordion.asp

如何配置在开始时打开的手风琴？

Javascript：

    <script>
var acc = document.getElementsByClassName("accordion");
var i;

for (i = 0; i < acc.length; i++) {
  acc[i].onclick = function() {
    this.classList.toggle("active");
    var panel = this.nextElementSibling;
    if (panel.style.maxHeight){
      panel.style.maxHeight = null;
    } else {
      panel.style.maxHeight = panel.scrollHeight + "px";
    } 
  }
}
</script>

Answer 1

只需在脚本末尾添加

acc[0].click();

<script>
var acc = document.getElementsByClassName("accordion");
var i;

for (i = 0; i < acc.length; i++) {
  acc[i].onclick = function() {
    this.classList.toggle("active");
    var panel = this.nextElementSibling;
    if (panel.style.maxHeight){
      panel.style.maxHeight = null;
    } else {
      panel.style.maxHeight = panel.scrollHeight + "px";
    } 
  }
}
acc[0].click();
</script>

Answer 2

您需要将类 .active 添加到 .accordion ，并将 style="display:block" 添加到要保持开放的子元素 p

var acc = document.getElementsByClassName("accordion");
var i;

for (i = 0; i < acc.length; i++) {
    acc[i].onclick = function(){
        this.classList.toggle("active");
        var panel = this.nextElementSibling;
        if (panel.style.display === "block") {
            panel.style.display = "none";
        } else {
            panel.style.display = "block";
        }
    }
}

button.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;
}

button.accordion.active, button.accordion:hover {
    background-color: #ddd; 
}

div.panel {
    padding: 0 18px;
    display: none;
    background-color: white;
}

<h2>Accordion</h2>

<button class="accordion active" >Section 1</button>
<div class="panel" style="display:block">
  <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">Section 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>
</div>

<button class="accordion">Section 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

如果我理解了这个问题，请尝试在文档加载时选择第一个（或其他）元素并将其显示设置为“块”：

acc[0].nextElementSibling.style.display = "block"