默认加载的选项卡内容

Question

这可能是一个微不足道的问题，但我想知道如何在页面自行加载时打开特定选项卡。在下文中，只有选项卡菜单，并且在单击任一选项卡后加载内容。取而代之的是，我可以在页面加载时加载并显示选项卡菜单和 "London" 的内容吗？

function openCity(evt, cityName) {
    // Declare all variables
    var i, tabcontent, tablinks;

    // Get all elements with class="tabcontent" and hide them
    tabcontent = document.getElementsByClassName("tabcontent");
    for (i = 0; i < tabcontent.length; i++) {
        tabcontent[i].style.display = "none";
    }

    // Get all elements with class="tablinks" and remove the class "active"
    tablinks = document.getElementsByClassName("tablinks");
    for (i = 0; i < tablinks.length; i++) {
        tablinks[i].className = tablinks[i].className.replace(" active", "");
    }

    // Show the current tab, and add an "active" class to the link that opened the tab
    document.getElementById(cityName).style.display = "block";
    evt.currentTarget.className += " active";
}

 /* Style the list */
ul.tab {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

/* Float the list items side by side */
ul.tab li {float: left;}

/* Style the links inside the list items */
ul.tab li a {
    display: inline-block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    transition: 0.3s;
    font-size: 17px;
}

/* Change background color of links on hover */
ul.tab li a:hover {background-color: #ddd;}

/* Create an active/current tablink class */
ul.tab li a:focus, .active {background-color: #ccc;}

/* Style the tab content */
.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}

 <ul class="tab">
  <li><a href="#" class="tablinks" onclick="openCity(event, 'London')">London</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, 'Paris')">Paris</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, 'Tokyo')">Tokyo</a></li>
</ul>

<div id="London" class="tabcontent">
  <h3>London</h3>
  <p>London is the capital city of England.</p>
</div>

<div id="Paris" class="tabcontent">
  <h3>Paris</h3>
  <p>Paris is the capital of France.</p>
</div>

<div id="Tokyo" class="tabcontent">
  <h3>Tokyo</h3>
  <p>Tokyo is the capital of Japan.</p>
</div>

Answer 1

你可以在 css 定义你的 tabcontent 首先 display block 像这样

.tabcontent:nth-of-type(1){display:block;}

function openCity(evt, cityName) {
    // Declare all variables
    var i, tabcontent, tablinks;

    // Get all elements with class="tabcontent" and hide them
    tabcontent = document.getElementsByClassName("tabcontent");
    for (i = 0; i < tabcontent.length; i++) {
        tabcontent[i].style.display = "none";
    }

    // Get all elements with class="tablinks" and remove the class "active"
    tablinks = document.getElementsByClassName("tablinks");
    for (i = 0; i < tablinks.length; i++) {
        tablinks[i].className = tablinks[i].className.replace(" active", "");
    }

    // Show the current tab, and add an "active" class to the link that opened the tab
    document.getElementById(cityName).style.display = "block";
    evt.currentTarget.className += " active";
}

 /* Style the list */
ul.tab {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

/* Float the list items side by side */
ul.tab li {float: left;}

/* Style the links inside the list items */
ul.tab li a {
    display: inline-block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    transition: 0.3s;
    font-size: 17px;
}

/* Change background color of links on hover */
ul.tab li a:hover {background-color: #ddd;}

/* Create an active/current tablink class */
ul.tab li a:focus, .active {background-color: #ccc;}

/* Style the tab content */
.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}
.tabcontent:nth-of-type(1){display:block;}

 <ul class="tab">
  <li><a href="#" class="tablinks" onclick="openCity(event, 'London')">London</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, 'Paris')">Paris</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, 'Tokyo')">Tokyo</a></li>
</ul>

<div id="London" class="tabcontent">
  <h3>London</h3>
  <p>London is the capital city of England.</p>
</div>

<div id="Paris" class="tabcontent">
  <h3>Paris</h3>
  <p>Paris is the capital of France.</p>
</div>

<div id="Tokyo" class="tabcontent">
  <h3>Tokyo</h3>
  <p>Tokyo is the capital of Japan.</p>
</div>

============ 第二个选项是你可以在 html 中 deinfe 默认显示给一个

function openCity(evt, cityName) {
    // Declare all variables
    var i, tabcontent, tablinks;

    // Get all elements with class="tabcontent" and hide them
    tabcontent = document.getElementsByClassName("tabcontent");
    for (i = 0; i < tabcontent.length; i++) {
        tabcontent[i].style.display = "none";
    }

    // Get all elements with class="tablinks" and remove the class "active"
    tablinks = document.getElementsByClassName("tablinks");
    for (i = 0; i < tablinks.length; i++) {
        tablinks[i].className = tablinks[i].className.replace(" active", "");
    }

    // Show the current tab, and add an "active" class to the link that opened the tab
    document.getElementById(cityName).style.display = "block";
    evt.currentTarget.className += " active";
}

 /* Style the list */
ul.tab {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

/* Float the list items side by side */
ul.tab li {float: left;}

/* Style the links inside the list items */
ul.tab li a {
    display: inline-block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    transition: 0.3s;
    font-size: 17px;
}

/* Change background color of links on hover */
ul.tab li a:hover {background-color: #ddd;}

/* Create an active/current tablink class */
ul.tab li a:focus, .active {background-color: #ccc;}

/* Style the tab content */
.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}

 <ul class="tab">
  <li><a href="#" class="tablinks active" onclick="openCity(event, 'London')">London</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, 'Paris')">Paris</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, 'Tokyo')">Tokyo</a></li>
</ul>

<div id="London" class="tabcontent" style=display:block;>
  <h3>London</h3>
  <p>London is the capital city of England.</p>
</div>

<div id="Paris" class="tabcontent">
  <h3>Paris</h3>
  <p>Paris is the capital of France.</p>
</div>

<div id="Tokyo" class="tabcontent">
  <h3>Tokyo</h3>
  <p>Tokyo is the capital of Japan.</p>
</div>

Answer 2

一种解决方案可以是模拟点击。

添加这个：

document.getElementsByClassName("tablinks")[0].click();

function openCity(evt, cityName) {
    // Declare all variables
    var i, tabcontent, tablinks;

    // Get all elements with class="tabcontent" and hide them
    tabcontent = document.getElementsByClassName("tabcontent");
    for (i = 0; i < tabcontent.length; i++) {
        tabcontent[i].style.display = "none";
    }

    // Get all elements with class="tablinks" and remove the class "active"
    tablinks = document.getElementsByClassName("tablinks");
    for (i = 0; i < tablinks.length; i++) {
        tablinks[i].className = tablinks[i].className.replace(" active", "");
    }

    // Show the current tab, and add an "active" class to the link that opened the tab
    document.getElementById(cityName).style.display = "block";
    evt.currentTarget.className += " active";
}

document.getElementsByClassName("tablinks")[0].click();

/* Style the list */
ul.tab {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

/* Float the list items side by side */
ul.tab li {float: left;}

/* Style the links inside the list items */
ul.tab li a {
    display: inline-block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    transition: 0.3s;
    font-size: 17px;
}

/* Change background color of links on hover */
ul.tab li a:hover {background-color: #ddd;}

/* Create an active/current tablink class */
ul.tab li a:focus, .active {background-color: #ccc;}

/* Style the tab content */
.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}

<ul class="tab">
  <li><a href="#" class="tablinks" onclick="openCity(event, 'London')">London</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, 'Paris')">Paris</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, 'Tokyo')">Tokyo</a></li>
</ul>

<div id="London" class="tabcontent">
  <h3>London</h3>
  <p>London is the capital city of England.</p>
</div>

<div id="Paris" class="tabcontent">
  <h3>Paris</h3>
  <p>Paris is the capital of France.</p>
</div>

<div id="Tokyo" class="tabcontent">
  <h3>Tokyo</h3>
  <p>Tokyo is the capital of Japan.</p>
</div>

Answer 3

尝试

.tabcontent:first-child{
    display:block;
}

默认加载的选项卡内容

Tab content loaded by default

html

javascript

css

tabs

load