如何使Bootstrap轮播字幕垂直居中？

Question

我有一个自举轮播，并且我正在尝试为该轮播创建标题，该标题始终垂直居中并稍微向左定位。我有用于水平定位的css。但是当我尝试垂直定位时，字幕不会停留在原处。如何使.carousel字幕始终保持垂直居中，并稍微向左对齐？

HTML：

    <!-- start JumboCarousel -->
    <div id="jumboCarousel" class="carousel slide" data-ride="carousel">

        <!-- Indicators -->
        <ol class="carousel-indicators hidden-xs">
            <li data-target="#jumboCarousel" data-slide-to="0" class="active"></li>
            <li data-target="#jumboCarousel" data-slide-to="1"></li>
            <li data-target="#jumboCarousel" data-slide-to="2"></li>
            <li data-target="#jumboCarousel" data-slide-to="3"></li>
        </ol><!-- end carousel-indicators -->

        <!-- Wrapper for Slides -->
        <div class="carousel-inner" role="listbox">
            <div class="item active" id="slide1">
                <a href="#"><img src="http://placehold.it/1920x720&text=Slide+1" alt="Slide 1"></a>
                <div class="carousel-caption">
                    <h1>Check Out this Moose</h1>
                    <p class="lead">This text is super engaging and makes you want to click the button.</p>
                    <a href="#" class="btn btn-lg btn-primary">Learn More</a>
                </div><!-- end carousel-caption -->
            </div><!-- end slide1 -->
            <div class="item" id="slide2">
                <img src="http://placehold.it/1920x720&text=Slide+2" alt="Slide 2">
                <div class="carousel-caption">
                    <h1>#Slide Title</h1>
                    <p class="lead">This text is super engaging and makes you want to click the button.</p>
                    <a href="#" class="btn btn-lg btn-primary">Learn More</a>
                </div><!-- end carousel-caption -->
            </div><!-- end slide2 -->
            <div class="item" id="slide3">
                <img src="http://placehold.it/1920x720&text=Slide+3" alt="Slide 3">
                <div class="carousel-caption">
                    <h1>#Slide Title</h1>
                    <p class="lead">This text is super engaging and makes you want to click the button.</p>
                    <a href="#" class="btn btn-lg btn-primary">Learn More</a>
                </div><!-- end carousel-caption -->
            </div><!-- end slide3 -->
            <div class="item" id="slide4">
                <img src="http://placehold.it/1920x720&text=Slide+4" alt="Slide 4">
                <div class="carousel-caption">
                    <h1>#Slide Title</h1>
                    <p class="lead">This text is super engaging and makes you want to click the button.</p>
                    <button type="button" href="#" class="btn btn-lg btn-primary">Learn More</button>
                </div><!-- end carousel-caption -->
            </div><!-- end slide4 -->
        </div><!-- end carousel-inner -->

    </div><!-- end jumboCarousel -->

CSS：

#jumboCarousel {
    margin-top: 70px;
    min-height: 300px;
    min-width: 100%;
}
#jumboCarousel img {
    min-height: 300px;
    min-width: 100%;
}
#jumboCarousel > .carousel-indicators > li {
    border-radius: 0px;
    min-width: 25px;
    background-color: #9d9d9d;
    border: 1px solid black;
    margin-right: 10px;;
    margin-left: 10px;;
}
#jumboCarousel > .carousel-indicators > .active {
    background-color: orange;
}
#jumboCarousel .carousel-caption {
    color: black;
    right: 58%;
    text-align: center;
    max-width: 500px;
    left: auto;
    top: auto;
}

为了使字幕垂直对齐，我所做的任何事情都随着屏幕尺寸减小，字幕被从轮播的顶部推出。.谢谢您的帮助。

Answer 1

您可以使用translateYCSS属性的功能transform垂直对齐元素。浏览器支持相当不错，包括IE9。因此，只需将以下内容添加到您的.carousel-captionCSS中即可。

top: 50%;
transform: translateY(-50%);

现在，您需要摆脱bottom默认引导CSS添加的额外空间。将以下内容也添加到您的.carousel-captionCSS中。

bottom: initial;

最后但并非最不重要的一点是，在这种情况下.item，为父元素提供以下CSS，以防止将其放置在半像素上时出现模糊的元素。

-webkit-transform-style: preserve-3d;
-moz-transform-style: preserve-3d;
transform-style: preserve-3d;