html - 纯CSS子菜单垂直

Question

我用这段代码得到了一个 css3 菜单:

HTML:

<div id="navi">
    <ul>
        <li><a href="#">First</a></li>
        <li class="active"><a href="#">Second</a>
            <ul class="child">
                <li><a href="#">First child</a></li>
            </ul>
        </li>
        <li><a href="#">Third</a></li>
    </ul>
</div>

CSS:

#navi {
    height: auto;
    width: auto;
}
#navi ul {
    margin: 0px;
    padding: 0px;
    list-style-type: none;
}
#navi ul li {
    float: left;
    position: relative;
}
#navi ul li a {
    line-height: 30px;
    text-decoration: none;
    text-align: center;
    display: block;
    width: 100px;
    height: 30px;
    border: thin solid #999;
    color: #FFF;
    background-color: #0CF;
    -webkit-transition: all 1s;
    -moz-transition: all 1s;
    -ms-transition: all 1s;
    -o-transition: all 1s;
    transition: all 1s;
}
#navi ul li a:hover {
    background-color: #0C3;
}
#navi ul li ul {
    position: absolute;
    -webkit-transition: height 1s linear 0s;
    -moz-transition: height 1s linear 0s;
    -ms-transition: height 1s linear 0s;
    -o-transition: height 1s linear 0s;
    transition: height 1s linear 0s;
    height: 0px;
    overflow:hidden;
}
#navi ul li:hover ul {
    height: 100px;
    -webkit-transition: height 1s linear 0s;
    -moz-transition: height 1s linear 0s;
    -ms-transition: height 1s linear 0s;
    -o-transition: height 1s linear 0s;
    transition: height 1s linear 0s;
}

fiddle Here

现在我希望菜单不是水平的。它应该是垂直的。我试图删除 float:left; 但是子菜单没有显示。子菜单应该按下下面的所有菜单项。有什么建议么？会很棒。

Answer 1

如果你这样做，它会给它完美的外观，并将你的 nav 向下推三项。将此高度添加到您的特定类(class):

#navi ul li:hover ul {
    height:32px;
}

但是，如果您在其他主 nav 项中有其他子菜单项，其中包含不同的项，那么您应该为所有特定元素创建类并根据它们赋予它们高度。看看这个:

#navi ul li:hover .class {
    height:64px; /*for two items in sub menu and like this for other*/ 
}