Bootstrap Carousel - 如何在幻灯片之间缓慢淡入淡出

我正在使用最新的 Bootstrap Carousel，需要在幻灯片之间缓慢淡出（大约 5 秒）。我看过很多例子，并尝试实现这个one https://stackoverflow.com/questions/27861435/bootstrap-carousel-refuses-to-transition-smoothly-after-css-adjustments/27870468。问题是幻灯片之间的淡入淡出太快（不到一秒）。我如何将其更改为更长的淡入淡出？

这是我的代码：

<div class="carousel slide" id="slideshow-carousel-1" data-ride="carousel">
    <div class="carousel-inner" role="listbox">
        <!-- Slide 1 -->
        <div class="item item-1 slide-image active">
            <img class="img-responsive bg-item parallax" data-speed="1" data-width="1980" data-height="1485" src="~/images/slideshow/bottle1.png" alt="Slide 1 Background">
            <div class="carousel-caption">
                <h1 class="title">Caption 1</h1>
            </div>
        </div>
        <!-- End Slide 1 -->

        <!-- Slide 2 -->
        <div class="item item-2 slide-image">
            <img class="img-responsive bg-item parallax" data-speed="1" data-width="1980" data-height="1485" src="~/images/slideshow/bottle2.jpg" alt="Slide 2 Background">
            <div class="carousel-caption">
                <h1 class="title">Or Bottle!</h1>
            </div>
        </div>
        <!-- End Slide 2 -->
    </div>
</div>

这是 CSS：

.carousel-inner > .item {
  opacity: 0;
  top: 0;
  left: 0;
  width: 100%;
  display: block;
  position: absolute;
  z-index: 0;
  -webkit-transition: opacity 5s ease;
       -o-transition: opacity 5s ease;
          transition: opacity 5s ease;
  -webkit-transform: translate3d(0, 0, 0) !important;
          transform: translate3d(0, 0, 0) !important;
}
.carousel-inner > .item:first-of-type {
  position: relative;
}
.carousel-inner > .active {
  opacity: 1;
  z-index: 3;
}
.carousel-inner > .next.left,
.carousel-inner > .prev.right {
  -webkit-transition: opacity 0.6s ease-in-out;
       -o-transition: opacity 0.6s ease-in-out;
          transition: opacity 0.6s ease-in-out;
  opacity: 1;
  left: 0;
  z-index: 2;
}
.carousel-inner > .active.left,
.carousel-inner > .active.right {
  z-index: 1;
}
.carousel-control {
  z-index: 4;
}

正如我已故的伟大计算机科学教授常说的那样，这个解决方案并不简单。这光滑的旋转木马 http://kenwheeler.github.io/slick/（Bootstrap Carousel 的衍生品）使用class="sld-transition-2"（三个可用类之一）在 body 标记上设置轮播的过渡。这与我试图设置的淡入淡出过渡相冲突。所以它被删除了。

提供的CSS3解决方案here http://codepen.io/transportedman/pen/NPWRGq?editors=110来自这个 Stackoverflowanswer https://stackoverflow.com/questions/26770055/bootstrap-carousel-fade-no-longer-working-with-maxcdn-3-3-bootstrap-min-css@transportedman 的作品是关键。我根据我们的要求对其进行了一些修改，并将其放置在要为站点加载的最后一个 CSS 文件中（以覆盖之前的所有内容）：

/*
inspired from http://codepen.io/Rowno/pen/Afykb 
https://stackoverflow.com/questions/26770055/bootstrap-carousel-fade-no-longer-working-with-maxcdn-3-3-bootstrap-min-css
*/
.carousel-fade .carousel-inner .item {
  opacity: 0;
  transition-property: opacity;
  transition-duration: 4s;
  transition-timing-function:linear;
}

.carousel-fade .carousel-inner .active {
  opacity: 1;
}

.carousel-fade .carousel-inner .active.left,
.carousel-fade .carousel-inner .active.right {
  left: 0;
  opacity: 0;
  z-index: 1;
}

.carousel-fade .carousel-inner .next.left,
.carousel-fade .carousel-inner .prev.right {
  opacity: 1;
}

.carousel-fade .carousel-control {
  z-index: 2;
}

/*
WHAT IS NEW IN 3.3: "Added transforms to improve carousel performance in modern browsers."
now override the 3.3 new styles for modern browsers & apply opacity
*/
@media all and (transform-3d), (-webkit-transform-3d) {
    .carousel-fade .carousel-inner > .item.next,
    .carousel-fade .carousel-inner > .item.active.right {
      opacity: 0;
      -webkit-transform: translate3d(0, 0, 0);
              transform: translate3d(0, 0, 0);
    }
    .carousel-fade .carousel-inner > .item.prev,
    .carousel-fade .carousel-inner > .item.active.left {
      opacity: 0;
      -webkit-transform: translate3d(0, 0, 0);
              transform: translate3d(0, 0, 0);
    }
    .carousel-fade .carousel-inner > .item.next.left,
    .carousel-fade .carousel-inner > .item.prev.right,
    .carousel-fade .carousel-inner > .item.active {
      opacity: 1;
      -webkit-transform: translate3d(0, 0, 0);
              transform: translate3d(0, 0, 0);
    }
}

最后但并非最不重要的一点是，修改轮播 DIV 标签以具有data-interval属性，它比transition-duration在上面的CSS3中设置：

<div class="carousel slide carousel-fade" id="slideshow-carousel-1" data-ride="carousel" data-interval="7000">
.....
</div>

希望这可以帮助遇到类似问题的其他人。