html - 下拉菜单全部左对齐

Question

我通过 CSS 创建了一个下拉菜单，但奇怪的是所有下拉菜单都左对齐。我希望所有的下拉菜单都出现在它们的父菜单下。

HTML 如下:-

<div id="menu">
        <ul>
          <li ng-class="{selected: $index==currPage}" ng-repeat="page in data.pages" class="ng-scope selected">
                <a href="" ng-click="goToPage($index)" class="ng-binding">Introduction</a>
                <ul>
                    <!-- ngRepeat: smenu in data.subMenu[$index].list --><li ng-class="{$index==currMenu}" ng-repeat="smenu in data.subMenu[$index].list" class="ng-scope">
                        <a href="" ng-click="goToPage($index)" class="ng-binding">Profile</a>

                    </li><li ng-class="{$index==currMenu}" ng-repeat="smenu in data.subMenu[$index].list" class="ng-scope">
                        <a href="" ng-click="goToPage($index)" class="ng-binding">Background</a>

                    </li><li ng-class="{$index==currMenu}" ng-repeat="smenu in data.subMenu[$index].list" class="ng-scope">
                        <a href="" ng-click="goToPage($index)" class="ng-binding">What is KAM</a>

                    </li>
                </ul>
            </li>
            ...
    </div>

以下是 CSS:-

#menu {
    /*border-bottom:4px seagreen solid;*/
    background-color: #2d394d;

    list-style:none;
}

#menu ul {
    list-style: none;
}

#menu ul li {
    display: inline-block;
    float: none;
    /*width: 20%;*/
}


#menu ul li a{
    font-size: 10pt;
    padding:12px 24px 12px 24px;
    /*border-right:1px white solid;*/
    display:block;
    text-decoration: none;
    text-align: center;
    color:#fff;
    text-transform: uppercase;
}

#menu ul li a:hover{
}

#menu ul li.selected a {
    background-color: #1b86c2;
    color:#fff;
}


/* DropDown Menus */

#menu ul ul{
    background:#fff; /* Adding a background makes the dropdown work properly in IE7+. Make this as close to your page's background as possible (i.e. white page == white background). */
    background:rgba(255,255,255,0); /* But! Let's make the background fully transparent where we can, we don't actually want to see it if we can help it... */
    list-style:none;
    position:absolute;
    left:-9999px; /* Hide off-screen when not needed (this is more accessible than display:none;) */
}
#menu ul li ul li{
    padding-top:1px; /* Introducing a padding between the li and the a give the illusion spaced items */
    float:none;
    display: block;
}
#nav ul ul a{
    white-space:nowrap; /* Stop text wrapping and creating multi-line dropdown items */
}
#menu li:hover ul{ /* Display the dropdown on hover */
    left:0; /* Bring back on-screen when needed */
}
#menu li:hover a{ /* These create persistent hover states, meaning the top-most link stays 'hovered' even when your cursor has moved down the list. */
    background:#1b86c2;
    text-decoration:underline;
}
#menu li:hover ul a{ /* The persistent hover state does however create a global style for links even before they're hovered. Here we undo these effects. */
    text-decoration:none;
}
#menu li:hover ul li a:hover{ /* Here we define the most explicit hover states--what happens when you hover each individual link. */
    background:#333;
}

你可以在这里看到显示它的图片(图片显示“案例”的下拉菜单，它应该在案例下面，但它向左移动了。“介绍”子菜单也显示在同一位置):-

Answer 1

这是因为left:0定位和父li的位置默认为static。你可以通过将其标记为相对的来修复它，这样子 ul 的 left:0 将相对于父 li。

#menu ul li {
    display: inline-block;
    float: none;
    /*width: 20%;*/
    position:relative; /*Add this*/
}

#menu li:hover ul{ /* Display the dropdown on hover */
     /* Bring back on-screen when needed */
    left:0;
    padding:0; /*Add this if you are not using any reset*/
}

Fiddle