Combine :after with :hover

Question

我想在CSS (或任何其他伪选择器)中结合使用:after和:hover。基本上，我有一个list，并且使用:after应用了selected类的项目的箭头形状。我希望同样的情况也适用于悬停在上面的对象，但不能完全让它工作。下面是代码

​

#alertlist {
  list-style: none;
  width: 250px;
}

#alertlist li {
  padding: 5px 10px;
  border-bottom: 1px solid #e9e9e9;
  position: relative;
}

#alertlist li.selected,
#alertlist li:hover {
  color: #f0f0f0;
  background-color: #303030;
}

#alertlist li.selected:after {
  position: absolute;
  top: 0;
  right: -10px;
  bottom: 0;
  border-top: 10px solid transparent;
  border-bottom: 10px solid transparent;
  border-left: 10px solid #303030;
  content: "";
}

<ul id="alertlist">
  <li>Alert 123</li>
  <li class="selected">Alert 123</li>
  <li>Alert 123</li>
</ul>

​

Answer 1

只需将:after附加到#alertlist li:hover选择器，就像处理#alertlist li.selected选择器一样：

#alertlist li.selected:after, #alertlist li:hover:after
{
    position:absolute;
    top: 0;
    right:-10px;
    bottom:0;

    border-top: 10px solid transparent;
    border-bottom: 10px solid transparent;
    border-left: 10px solid #303030;
    content: "";
}

Answer 2

在scss中

&::after{
content: url(images/RelativeProjectsArr.png);
margin-left:30px;
}

&:hover{
    background-color:$turkiz;
    color:#e5e7ef;

    &::after{
    content: url(images/RelativeProjectsArrHover.png);
    }
}

Answer 3

 #alertlist li:hover:after,#alertlist li.selected:after
{
    position:absolute;
    top: 0;
    right:-10px;
    bottom:0;

    border-top: 10px solid transparent;
    border-bottom: 10px solid transparent;
    border-left: 10px solid #303030;
    content: "";
}​

jsFiddle Link