Bootstarp 4 入门之轮播图

轮播Carousel

幻灯片组件，用于循环显示元素（图像或文本幻灯片），例如轮播。

<div id="carouselExampleSlidesOnly" class="carousel slide" data-ride="carousel">
  <div class="carousel-inner">
    <div class="carousel-item active">
        <img src="..." class="d-block w-100" alt="...">
    </div>
    <div class="carousel-item">
      <img src="..." class="d-block w-100" alt="...">
    </div>
    <div class="carousel-item">
      <img src="..." class="d-block w-100" alt="...">
    </div>
  </div>
</div>

带左右箭头carousel-control-prev-icon,carousel-control-next

  <a class="carousel-control-prev" href="#carouselExampleControls" role="button" data-slide="prev">
    <span class="carousel-control-prev-icon" aria-hidden="true"></span>
    <span class="sr-only">Previous</span>
  </a>
  <a class="carousel-control-next" href="#carouselExampleControls" role="button" data-slide="next">
    <span class="carousel-control-next-icon" aria-hidden="true"></span>
    <span class="sr-only">Next</span>
  </a>

带指示器 carousel-indicators

  <ol class="carousel-indicators">
    <li data-target="#carouselExampleIndicators" data-slide-to="0" class="active"></li>
    <li data-target="#carouselExampleIndicators" data-slide-to="1"></li>
    <li data-target="#carouselExampleIndicators" data-slide-to="2"></li>
  </ol>

包含字幕 carousel-caption

<div id="carouselExampleCaptions" class="carousel slide" data-ride="carousel">
  <ol class="carousel-indicators">
    <li data-target="#carouselExampleCaptions" data-slide-to="0" class="active"></li>
    <li data-target="#carouselExampleCaptions" data-slide-to="1"></li>
    <li data-target="#carouselExampleCaptions" data-slide-to="2"></li>
  </ol>
  <div class="carousel-inner">
    <div class="carousel-item active">
      <img src="..." class="d-block w-100" alt="...">
      <div class="carousel-caption d-none d-md-block">
        <h5>First slide label</h5>
        <p>Nulla vitae elit libero, a pharetra augue mollis interdum.</p>
      </div>
    </div>
    <div class="carousel-item">
      <img src="..." class="d-block w-100" alt="...">
      <div class="carousel-caption d-none d-md-block">
        <h5>Second slide label</h5>
        <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
      </div>
    </div>
    <div class="carousel-item">
      <img src="..." class="d-block w-100" alt="...">
      <div class="carousel-caption d-none d-md-block">
        <h5>Third slide label</h5>
        <p>Praesent commodo cursus magna, vel scelerisque nisl consectetur.</p>
      </div>
    </div>
  </div>
  <a class="carousel-control-prev" href="#carouselExampleCaptions" role="button" data-slide="prev">
    <span class="carousel-control-prev-icon" aria-hidden="true"></span>
    <span class="sr-only">Previous</span>
  </a>
  <a class="carousel-control-next" href="#carouselExampleCaptions" role="button" data-slide="next">
    <span class="carousel-control-next-icon" aria-hidden="true"></span>
    <span class="sr-only">Next</span>
  </a>
</div>

特效

淡入淡出 .carousel-fade

<div id="carouselExampleFade" class="carousel slide carousel-fade" data-ride="carousel">...</div>

时间间隔 ,添加data-interval=""到.carousel-item可以更改自动循环至下一个项目之间的延迟时间

<div id="carouselExampleInterval" class="carousel slide" data-ride="carousel">
  <div class="carousel-inner">
    <div class="carousel-item active" data-interval="10000">
      <img src="..." class="d-block w-100" alt="...">
    </div>
    <div class="carousel-item" data-interval="2000">
      <img src="..." class="d-block w-100" alt="...">
    </div>
    <div class="carousel-item">
      <img src="..." class="d-block w-100" alt="...">
    </div>
  </div>
  <a class="carousel-control-prev" href="#carouselExampleInterval" role="button" data-slide="prev">
    <span class="carousel-control-prev-icon" aria-hidden="true"></span>
    <span class="sr-only">Previous</span>
  </a>
  <a class="carousel-control-next" href="#carouselExampleInterval" role="button" data-slide="next">
    <span class="carousel-control-next-icon" aria-hidden="true"></span>
    <span class="sr-only">Next</span>
  </a>
</div>

通过 data 属性

js控制

• .carousel('cycle')
  从左到右循环浏览轮播项目。

• .carousel('pause')
  阻止轮播在各个项目之间循环。

• .carousel(number)
  将轮播循环到特定帧（从0开始，类似于数组）。在显示目标项目之前（即slid.bs.carousel事件发生之前）返回到调用方。

• .carousel('prev')
  循环到上一个项目。在显示上一个项目之前（即在slid.bs.carousel事件发生之前）返回到呼叫者。

• .carousel('next')
  循环到下一个项目。在显示下一项之前（即在slid.bs.carousel事件发生之前）返回到呼叫者。

• .carousel('dispose')
  销毁元素的轮播。

  $('.carousel').carousel({
  interval: 2000
  })

回调事件

Bootstrap的轮播类展示了两个挂钩到轮播功能的事件。这两个事件具有以下附加属性：

• direction：轮播的滑动方向（"left"或"right"）。
• relatedTarget：作为活动项目滑入到位的DOM元素。
• from：当前项目的索引
• to：下一项的索引