快速解决bootstrap下拉菜单无法隐藏的问题
时间：2021-04-16 08:23:54|栏目：JavaScript代码|点击： 次
下拉菜单的两种实现
想必大家都知道，bootstrap为我们提供了一个下拉菜单的组件，官方也为我们提供两种使用方法
1.标签指定data-toggle
<div class="dropdown">
<button type="button" class="btn dropdown-toggle" id="dropdownMenu1" data-toggle="dropdown">主题
<span class="caret"></span>
</button>
<ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu1">
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Java</a>
</li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >数据挖掘</a>
</li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >数据通信/网络</a>
</li>
<li role="presentation" class="divider"></li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >分离的链接</a>
</li>
</ul>
</div>
2.js调用dropdown(‘toggle')方法
<div class="dropdown">
<a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="dropdown-toggle" id="dropdownMenu1" >
主题
<span class="caret"></span>
</a>
<ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu1">
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Java</a>
</li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >数据挖掘</a>
</li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >数据通信/网络</a>
</li>
</ul>
<button id="test">test</button>
</div>
</body>
<script>
$(function() {
$("#test").click(function() {
$(".dropdown-toggle").dropdown('toggle');
})
})
</script>
第二种方法有个很严重的问题
就是，下拉菜单开启后，官方并没有提供将它隐藏的方法，网上的方法死活说再次调用dropdown(‘toggle')。。。反正我不行。
那么我想用点击之外来开启下拉菜单呢？（必须得使用JS来控制）
我想到一个方法，使用jQuery提供的一个效果slideUp(),slideDown()
<body>
<div class="dropdown">
<a href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" class="dropdown-toggle" id="dropdownMenu1" >
主题
<span class="caret"></span>
</a>
<ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu1">
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >Java</a>
</li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >数据挖掘</a>
</li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >数据通信/网络</a>
</li>
<li role="presentation" class="divider"></li>
<li role="presentation">
<a role="menuitem" tabindex="-1" href="#" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >分离的链接</a>
</li>
</ul>
<button id="test">test</button>
<button id="test1">test1</button>
</div>
</body>
<script>
$(function() {
$("#test").click(function() {
$(".dropdown-menu").slideUp();
})
$("#test1").click(function() {
$(".dropdown-menu").slideDown();
})
})
</script>
好了现在能实现开和关了，但是速度有点慢？没事slide可以通过参数调节速度甚至还有回调函数来替代$(selector).on("hidden.bs.dropdown', function () {})（对下拉菜单收回时间的监听），满分！
$(selector).slideUp(speed,callback)
speed 可选。规定元素从可见到隐藏的速度（或者相反）。默认为 “normal”。 可能的值：
毫秒 （比如 1500）
“slow”
“normal”
“fast”
在设置速度的情况下，元素从可见到隐藏的过程中，会逐渐地改变其高度（这样会创造滑动效果）。
callback
可选。slideUp 函数执行完之后，要执行的函数。 除非设置了 speed 参数，否则不能设置该参数。
