Question

我有滚动条的多级下拉菜单。但它不会显示3级子菜单。请建议我这个。

＆＃13;

.dropdown-submenu {
    position: relative;
}

.dropdown-submenu>.dropdown-menu {
    top: 0;
    left: 100%;
    margin-top: -6px;
    margin-left: -1px;
    -webkit-border-radius: 0 6px 6px 6px;
    -moz-border-radius: 0 6px 6px;
    border-radius: 0 6px 6px 6px;
    overflow-y: scroll;
    overflow-x: hidden;
    height: 80px;
}

.dropdown-submenu:hover>.dropdown-menu {
    display: block;
}

.dropdown-submenu>a:after {
    display: block;
    content: " ";
    float: right;
    width: 0;
    height: 0;
    border-color: transparent;
    border-style: solid;
    border-width: 5px 0 5px 5px;
    border-left-color: #ccc;
    margin-top: 5px;
    margin-right: -10px;
}

.dropdown-submenu:hover>a:after {
    border-left-color: #fff;
}

.dropdown-submenu.pull-left {
    float: none;
}

.dropdown-submenu.pull-left>.dropdown-menu {
    left: -100%;
    margin-left: 10px;
    -webkit-border-radius: 6px 0 6px 6px;
    -moz-border-radius: 6px 0 6px 6px;
    border-radius: 6px 0 6px 6px;
}

＆＃13;

<link href="http://netdna.bootstrapcdn.com/bootstrap/3.1.1/css/bootstrap.min.css" rel="stylesheet"/>
<script src="http://netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js"></script>
<div class="container">
	<div class="row">
       
        <div class="dropdown">
            <a id="dLabel" role="button" data-toggle="dropdown" class="btn btn-primary" data-target="#" href="/page.html">
                Dropdown <span class="caret"></span>
            </a>
    		<ul class="dropdown-menu multi-level" role="menu" aria-labelledby="dropdownMenu">
              <li><a href="#">Some action</a></li>
              <li><a href="#">Some other action</a></li>
              <li class="divider"></li>
              <li class="dropdown-submenu">
                <a tabindex="-1" href="#">Hover me for more options</a>
                <ul class="dropdown-menu">
                  <li><a tabindex="-1" href="#">Second level</a></li>
                  <li class="dropdown-submenu">
                    <a href="#">Even More..</a>
                    <ul class="dropdown-menu">
                        <li><a href="#">3rd level</a></li>
                        <li><a href="#">3rd level</a></li>
                        <li><a href="#">3rd level</a></li>
                        <li><a href="#">3rd level</a></li>
                        <li><a href="#">3rd level</a></li>
                        <li><a href="#">3rd level</a></li>
                    	<li><a href="#">3rd level</a></li>
                    </ul>
                  </li>
                  <li><a href="#">Second level</a></li>
                  <li><a href="#">Second level</a></li>
                </ul>
              </li>
            </ul>
        </div>
	</div>
</div>

＆＃13;

我希望子菜单应该从顶部开始。像这样https://ibb.co/jWeFwk， https://ibb.co/goO8Gk 请亲自去看看建议我需要修改css。

Answer 1

.dropdown-submenu>.dropdown-menu {
    top: 0;
    left: 100%;
    margin-top: -6px;
    margin-left: -1px;
    -webkit-border-radius: 0 6px 6px 6px;
    -moz-border-radius: 0 6px 6px;
    border-radius: 0 6px 6px 6px;

    /**
      * It's unnecessary.
      */
    /* overflow-y: scroll;
    overflow-x: scroll; 
    height: 80px; */
}

Answer 2

请在此处查看更新的小提琴：Fiddle

<div class="container">
<div class="row">

    <div class="dropdown">
        <a id="dLabel" role="button" data-toggle="dropdown" class="btn btn-primary" data-target="#" href="/page.html">
            Dropdown <span class="caret"></span>
        </a>
        <ul class="dropdown-menu multi-level" role="menu" aria-labelledby="dropdownMenu">
          <li><a href="#">Some action</a></li>
          <li><a href="#">Some other action</a></li>
          <li class="divider"></li>
          <li class="dropdown-submenu">
            <a tabindex="-1" href="#">Hover me for more options</a>
            <ul class="dropdown-menu">
              <li><a tabindex="-1" href="#">Second level</a></li>
              <li class="dropdown-submenu">
                <a href="#">Even More..</a>
                <ul class="dropdown-menu dropdown-menu-3">
                    <li><a href="#">3rd level</a></li>
                    <li><a href="#">3rd level</a></li>
                    <li><a href="#">3rd level</a></li>
                    <li><a href="#">3rd level</a></li>
                    <li><a href="#">3rd level</a></li>
                    <li><a href="#">3rd level</a></li>
                    <li><a href="#">3rd level</a></li>
                </ul>
              </li>
              <li><a href="#">Second level</a></li>
              <li><a href="#">Second level</a></li>
            </ul>
          </li>
        </ul>
    </div>
</div>

CSS：

.dropdown-submenu {
    position: relative;
}

.dropdown-submenu>.dropdown-menu {
    top: 0;
    left: 100%;
    margin-top: -6px;
    margin-left: -1px;
    -webkit-border-radius: 0 6px 6px 6px;
    -moz-border-radius: 0 6px 6px;
    border-radius: 0 6px 6px 6px;
    height: 120px;
}
.dropdown-submenu>.dropdown-menu-3{
    height: 196px;
}
.dropdown-submenu:hover>.dropdown-menu {
    display: block;
}

.dropdown-submenu>a:after {
    display: block;
    content: " ";
    float: right;
    width: 0;
    height: 0;
    border-color: transparent;
    border-style: solid;
    border-width: 5px 0 5px 5px;
    border-left-color: #ccc;
    margin-top: 5px;
    margin-right: -10px;
}

.dropdown-submenu:hover>a:after {
    border-left-color: #fff;
}

.dropdown-submenu.pull-left {
    float: none;
}

.dropdown-submenu.pull-left>.dropdown-menu {
    left: -100%;
    margin-left: 10px;
    -webkit-border-radius: 6px 0 6px 6px;
    -moz-border-radius: 6px 0 6px 6px;
    border-radius: 6px 0 6px 6px;
}

带滚动条问题的多级DropDown菜单

2 个答案: