<!--轮播组件向左向右的按钮-->

<a class="carousel-control left" href="#carousel-example-generic" data-slide="prev">

<span class="glyphicon glyphicon-chevron-left" ></span>

<span class="sr-only">上一页</span>

</a>

<a class="carousel-control right" href="#carousel-example-generic" data-slide="next">

<span class="glyphicon glyphicon-chevron-right" ></span>

<span class="sr-only">下一页</span>

</a>

之前的glyphicon的小图标也显示不出来，不知道应该怎么做，请大神指点