在CSS中启用页面加载时悬停

Question

我正在一个网站上希望启用页面加载时悬停。

我用于标签的HTML代码是：

<div class="tab">
  <button class="tablinks" onclick="openCity(event, 'London')">London</button>
  <button class="tablinks" onclick="openCity(event, 'Paris')">Paris</button>
  <button class="tablinks" onclick="openCity(event, 'Tokyo')">Tokyo</button>
</div>

我用来启用伦敦标签内容的CSS代码是：

.tab-contents>.active
{
display:block;
}

问题陈述：

我想知道我应该在小提琴中进行哪些更改，以便在页面加载时始终通过悬停启用伦敦选项卡。内容部分已启用，我现在只想使用鼠标悬停启用选项卡。

代码：

function openCity(evt, cityName) {
  var i, tabcontent, tablinks;
  tabcontent = document.getElementsByClassName("tabcontent");
  for (i = 0; i < tabcontent.length; i++) {
    tabcontent[i].style.display = "none";
  }
  tablinks = document.getElementsByClassName("tablinks");
  for (i = 0; i < tablinks.length; i++) {
    tablinks[i].className = tablinks[i].className.replace(" active", "");
  }
  document.getElementById(cityName).style.display = "block";
  evt.currentTarget.className += " active";
}

body {
  font-family: Arial;
}


/* Style the tab */

.tab {
  overflow: hidden;
  border: 1px solid #ccc;
  background-color: #f1f1f1;
}


/* Style the buttons inside the tab */

.tab button {
  background-color: inherit;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 14px 16px;
  transition: 0.3s;
  font-size: 17px;
}


/* Change background color of buttons on hover */

.tab button:hover {
  background-color: #ddd;
}


/* Create an active/current tablink class */

.tab button.active {
  background-color: #ccc;
}


/* Style the tab content */

.tabcontent {
  display: none;
  padding: 6px 12px;
  border: 1px solid #ccc;
  border-top: none;
}


/* Style the tab content */

.tab-contents>.active {
  display: block;
}

<p>Click on the buttons inside the tabbed menu:</p>

<div class="tab">
  <button class="tablinks" onclick="openCity(event, 'London')">London</button>
  <button class="tablinks" onclick="openCity(event, 'Paris')">Paris</button>
  <button class="tablinks" onclick="openCity(event, 'Tokyo')">Tokyo</button>
</div>

<div class="tab-contents">
  <div id="London" class="tabcontent active">
    <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>
</div>

Answer 1

如果悬停，则表示已选中。

然后，您只需附加对应的类（active）。

<button class="tablinks active" onclick="openCity(event, 'London')">London</button>

---

然后，您想在鼠标悬停时删除活动对象，只需更改它即可。 （仅当鼠标不在button.active上时应用.tab）

.tab:not(:hover) button.active {
   /*^^^^^^^^^^*/
    background-color: #ccc;
}

---

完整代码。

function openCity(evt, cityName) {
  var i, tabcontent, tablinks;
  tabcontent = document.getElementsByClassName("tabcontent");
  for (i = 0; i < tabcontent.length; i++) {
    tabcontent[i].style.display = "none";
  }
  tablinks = document.getElementsByClassName("tablinks");
  for (i = 0; i < tablinks.length; i++) {
    tablinks[i].className = tablinks[i].className.replace(" active", "");
  }
  document.getElementById(cityName).style.display = "block";
  evt.currentTarget.className += " active";
}

body {
  font-family: Arial;
}


/* Style the tab */

.tab-bar {
  overflow: hidden;
  border: 1px solid #ccc;
  background-color: #f1f1f1;
}


/* Style the buttons inside the tab */

.tab button {
  background-color: inherit;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 14px 16px;
  transition: 0.3s;
  font-size: 17px;
}


/* Change background color of buttons on hover */

.tab button:hover {
  background-color: #ddd;
}

/* Create an active/current tablink class */
.tab:not(:hover) button.active {
  background-color: #ccc;
}


/* Style the tab content */

.tabcontent {
  display: none;
  padding: 6px 12px;
  border: 1px solid #ccc;
  border-top: none;
}


/* Style the tab content */

.tab-contents>.active {
  display: block;
}

<p>Click on the buttons inside the tabbed menu:</p>

<div class="tab-bar">
  <div class="tab">
    <button class="tablinks active" onclick="openCity(event, 'London')">London</button>
    <button class="tablinks" onclick="openCity(event, 'Paris')">Paris</button>
    <button class="tablinks" onclick="openCity(event, 'Tokyo')">Tokyo</button>
  </div>
</div>

<div class="tab-contents">
  <div id="London" class="tabcontent active">
    <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>
</div>