javascript - 如何在左侧的下拉菜单中打开子菜单

Question

在下面的下拉菜单中，当我们将鼠标悬停在元素上时，子菜单会向右打开。但是，我希望它向左打开。

这里是代码:

html:

<div id="mn-wrapper">

    <div class="mn-sidebar">
        <div class="mn-toggle"><i class="fa fa-bars"></i></div>
        <div class="mn-navblock">
            <ul class="mn-vnavigation">
                <li class="dropdown-submenu active">
                    <a tabindex="-1" href="#">LARGE HOLDINGS</a>
            <ul class="dropdown-menu third-menu">
                <li class="dropdown-submenu active"><a href="#">LHO</a>

 <ul class="dropdown-menu parent third-menu">
                    <li style=" border-bottom: 1px solid #ccc;">
            <a href="#">Contact Us
            <span aria-hidden="true" class="glyphicon glyphicon-plus pull-right"></span>
            <span aria-hidden="true" class="glyphicon glyphicon-minus pull-right" style="display:none;"></span>
                </a>

<ul class="child">
<li style="padding:10px 0; color:white;"><font color = C8CBCC size = 2><b>Hotline:</b></font> 8828 5600</li>
<li style="padding:10px 0; color:white;"><font color = C8CBCC size = 2 ><b>Support Mailbox:</b></font> <font face = "Barclays Sans">Compliance Application 

Support L1</font></li>
</ul>
</li>

<li style=" border-bottom: 1px solid #ccc;">
<a href="#">Application Overview
<span aria-hidden="true" class="glyphicon glyphicon-plus pull-right"></span>
<span aria-hidden="true" class="glyphicon glyphicon-minus pull-right" style="display:none;"></span>
</a>

<ul class="child">
<li style="padding:10px 0; color:white;"><font color = C8CBCC size = 2><b>LHO </b></font></br></br><font size=2> Web Application to track large equity 

holdings and, where appropriate, report to regulators. It is owned by the Compliance Department.</font></li>
</ul>
</li>      
</ul>
</li>



         </ul>




</li>



 <li class="dropdown-submenu active">
                    <a tabindex="-1" href="#">ORCHESTRIA</a>
            <ul class="dropdown-menu third-menu">
                <li class="dropdown-submenu active"><a href="#">ORCHESTRIA</a>

 <ul class="dropdown-menu parent third-menu">
                    <li style=" border-bottom: 1px solid #ccc;">
            <a href="#">Contact Us
            <span aria-hidden="true" class="glyphicon glyphicon-plus pull-right"></span>
            <span aria-hidden="true" class="glyphicon glyphicon-minus pull-right" style="display:none;"></span>
                </a>

<ul class="child">
<li style="padding:10px 0; color:white;"><font color = C8CBCC size = 2><b>Hotline:</b></font> 8828 5600</li>
<li style="padding:10px 0; color:white;"><font color = C8CBCC size = 2 ><b>Support Mailbox:</b></font> <font face = "Barclays Sans">Compliance Application 

Support L1</font></li>
</ul>
</li>

<li style=" border-bottom: 1px solid #ccc;">
<a href="#">Application Overview
<span aria-hidden="true" class="glyphicon glyphicon-plus pull-right"></span>
<span aria-hidden="true" class="glyphicon glyphicon-minus pull-right" style="display:none;"></span>
</a>

<ul class="child">
<li style="padding:10px 0; color:white;"><font color = C8CBCC size = 2><b>ORCHESTRIA</b></font> </br></br><font size=2> E-mail and instant messaging 

monitoring and intelligent review using CA DLP.</font></li>
</ul>
</li>      
</ul>
</li>




         </ul>




</li>
</div>

</div>

</div>

CSS:

div.container {

margin-left: 5%;
margin-right: 10%;


}

div.box {
    box-sizing: border-box;
    width: 50%;
    border: 1em white;
    float: left;

}



nav {

/*background-image: url("http://teams.barclays.intranet/sites/compliancertb/Shared%20Documents/rtb3.bmp ");*/

background-color: #CCFFFF;
margin-left: 15px;
margin-right: 40px;

}


.back div {
width: 930px;
height: 400px;
background-color: #DBFFFF;
}

table {
    border-collapse: collapse;
}
td {
    padding: 0 13px 0 13px;
font-family: Barclays Sans;
font-size: 13px;
}


tr.spaceUnder > td
{
padding-bottom: 1em;



}


.third-menu{
    position: absolute;
    right:0;
    top:0;
}


.dropdown-submenu {
    border-bottom: 1px solid #ccc;
    position:relative;
}


#mn-wrapper {
  display: block;
  width: 100%;
  position: absolute;
    height: 30px;


}
.mn-sidebar {
  margin-left: 40px;
  display: block;
  position: relative;
  vertical-align: middle;
  padding-bottom: 1px;
    background: #333333;
    width: 250px;
    z-index: 2;
}


#mn-cont {
  display: block;
    vertical-align: top;     
    position: relative;
    padding: 10;
}
.container {
    margin-right: auto;
}
.cnt-mcont {
  background-color: #F6F6F6;
  color: inherit;
  font-size: 13px;
  font-weight: 200;
  line-height: 21px;
  padding: 15px 30px 30px 30px;
  margin-top: 0;
    height: 101vh;
}
.mn-sidebar .mn-toggle {
  display: none;
  padding: 10px 0;
  text-align: center;
    cursor: pointer;
}
.mn-vnavigation {
  margin: 0 0 0 0;
  padding: 0;
  border-top: 2px solid #CCFFFF;
    border-bottom: 1px solid #CCFFFF;
border-left: 5px solid #CCFFFF;
border-right: 5px solid #CCFFFF;

}
.mn-vnavigation li a {
  border-top: 2px solid #CCFFFF;
  border-bottom: 1px solid #CCFFFF;
  display: block;
  padding: 14px 18px 13px 15px;
  color: #fff;
  text-decoration: none;
  font-size: 12px;
  font-weight: 300;
  text-shadow: 1px 1px 0 rgba(0, 0, 0, 0.3);
    white-space: nowrap;
}
.dropdown-submenu >
.dropdown-menu {
    top: 0;
  left: 100%;
  margin-top: -6px;
  margin-left: -1px;
  /*height: 590px; */
  width: 310px;
  background: #333333;
}
.dropdown-submenu:hover > 
.dropdown-menu {

    display: list-item;
}


.dropdown-submenu > a:after {

    display: list-item;
    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;
}
ul {
    list-style: none;
}
ul.dropdown-menu.parent {
  margin-top: -1px;
}
.bottom-mn {
    bottom:0px;         
    position:absolute;
    width:100%;
}

js:

$('.child').hide(); //Hide children by default
$('.parent').children().click(function () {
    event.preventDefault();
    $(this).children('.child').slideToggle('slow');
    $(this).find('span').toggle();
});

然后codepen链接:

http://codepen.io/anon/pen/LpxVdv

请告诉我该怎么做？

Answer 1

您可以修改 .dropdown-submenu:hover > .dropdown-menu css 规则:

.dropdown-submenu:hover > .dropdown-menu {
    display: list-item;
    left: -310px;
}   

显然你需要在左侧留一个空间来容纳这个:

.mn-sidebar {
  margin-left: 600px;
  ...
}   

EDIT 基于以下 OP 评论:

.dropdown-submenu:hover > .dropdown-menu {
    display: list-item;
}
.dropdown-submenu:nth-child(2):hover > .dropdown-menu,
.dropdown-submenu:nth-child(2) > .dropdown-menu > .dropdown-submenu:hover > .dropdown-menu {
    display: list-item;
    left: -310px;
}