问题描述
我正在使用bootstrap-vue，并且我有一个多级下拉菜单（用于类别）。这是官方网站示例：
https://bootstrap-vue.org/docs/components/dropdown
<div class="fixed-top navbar navbar-light bg-light navbar-expand-md justify-content-center">
<div class="container">
<a class="navbar-brand" href="/"> Brand </a>
<button type="button" class="navbar-toggler" data-toggle="collapse" data-target=".navbar-collapse">☰</button>
<div class="navbar-collapse collapse">
<ul class="nav navbar-nav">
<li class="nav-item"><a href="#" class="nav-link">Home</a>
</li>
<li class="dropdown menu-large nav-item"> <a href="#" class="dropdown-toggle nav-link" data-toggle="dropdown">Categories </a>
<ul class="dropdown-menu megamenu">
<div class="container">
<div class="row">
<li class="col-md-3 dropdown-item">
<ul>
<li class="dropdown-header">Glyphicons</li>
<li><a href="#">Available glyphs</a>
</li>
<li class="disabled"><a href="#">How to use</a>
</li>
<li><a href="#">Examples</a>
</li>
<li class="divider"></li>
<li class="dropdown-header">Dropdowns</li>
<li><a href="#">Example</a>
</li>
<li><a href="#">Aligninment options</a>
</li>
<li><a href="#">Headers</a>
</li>
<li><a href="#">disabled menu items</a>
</li>
</ul>
</li>
<li class="col-md-3 dropdown-item">
<ul>
<li class="dropdown-header">Button groups</li>
<li><a href="#">Basic example</a>
</li>
<li><a href="#">Button toolbar</a>
</li>
<li><a href="#">Sizing</a>
</li>
<li><a href="#">nesting</a>
</li>
<li><a href="#">Vertical variation</a>
</li>
<li class="divider"></li>
<li class="dropdown-header">Button dropdowns</li>
<li><a href="#">Single</a>
</li>
</ul>
</li>
<li class="col-md-3 dropdown-item">
<ul>
<li class="dropdown-header">Input groups</li>
<li><a href="#">Basic example</a>
</li>
<li><a href="#">Sizing</a>
</li>
<li><a href="#">CheckBoxes</a>
</li>
<li class="divider"></li>
<li class="dropdown-header">Navs</li>
<li><a href="#">Tabs</a>
</li>
<li><a href="#">Pills</a>
</li>
<li><a href="#">Justified</a>
</li>
</ul>
</li>
<li class="col-md-3 dropdown-item">
<ul>
<li class="dropdown-header">Navbar</li>
<li><a href="#">Default navbar</a>
</li>
<li><a href="#">Buttons</a>
</li>
<li><a href="#">Text</a>
</li>
<li><a href="#">Non-nav links</a>
</li>
<li><a href="#">Component alignment</a>
</li>
<li><a href="#">Fixed to top</a>
</li>
<li><a href="#">Fixed to bottom</a>
</li>
<li><a href="#">Static top</a>
</li>
<li><a href="#">Inverted navbar</a>
</li>
</ul>
</li>
</div>
</div>
</ul>
</li>
</ul>
</div>
</div>
</div>
但是我不知道如何创建一个多级菜单（我在彼此内部复制下拉菜单，但是不起作用）！它只有1级下拉示例！我如何创建一个多层次的？
tnx
解决方法
因此，正如我在评论中提到的那样，您可以包装b-dropdown事件并执行类似的自定义操作：
<div id="app">
<b-dropdown id="dropdown-1" text="Dropdown Button 1" class="m-md-2">
<b-dropdown-item>First Action 1</b-dropdown-item>
<b-dropdown-item>Second Action 1</b-dropdown-item>
<b-dropdown id="dropdown-2" text="Dropdown Button 2" class="m-md-2">
<b-dropdown-item>First Action 2</b-dropdown-item>
<b-dropdown-item>Second Action 2</b-dropdown-item>
</b-dropdown>
</b-dropdown>
</div>
mounted: function () {
this.$root.$on('bv::dropdown::show',bvEvent => {
if(bvEvent.componentId === 'dropdown-2') {
this.isDropdown2Visible = true;
}
})
this.$root.$on('bv::dropdown::hide',bvEvent => {
if(bvEvent.componentId === 'dropdown-2') {
this.isDropdown2Visible = false;
}
if(this.isDropdown2Visible) {
bvEvent.preventDefault()
}
})
}
完整的示例，您可以在这里找到：Vue bootstrap nested dropdown
,您可以尝试这样的事情
此代码段包含一级菜单的逻辑。您可以将代码编辑为 根据您的要求
new Vue({
el: "#app",data: {
menu: [
{ title : 'one'},{ title : 'two'},{ title : 'three',showSubMenu : false,children : [
{ title : 'four'},{ title : 'five'},]},]
},methods : {
toogleItem(index){
if(this.menu[index].children){
if(!this.menu[index].showSubMenu){
this.menu[index].showSubMenu = true
} else {
this.menu[index].showSubMenu = false
}
}
}
}
}).sub-menu{
position: absolute;
min-width: 10rem;
padding: .5rem 0;
margin: .125rem 0 0;
font-size: 1rem;
color: #212529;
text-align: left;
list-style: none;
background-color: #fff;
background-clip: padding-box;
border: 1px solid rgba(0,.15);
border-radius: .25rem;
}<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>JS Bin</title>
<!-- Load required Bootstrap and BootstrapVue CSS -->
<link type="text/css" rel="stylesheet" href="//unpkg.com/bootstrap/dist/css/bootstrap.min.css" />
<link type="text/css" rel="stylesheet" href="//unpkg.com/bootstrap-vue@latest/dist/bootstrap-vue.min.css" />
<!-- Load polyfills to support older browsers -->
<script src="//polyfill.io/v3/polyfill.min.js?features=es2015%2CIntersectionObserver" crossorigin="anonymous"></script>
<!-- Load Vue followed by BootstrapVue -->
<script src="//unpkg.com/vue@latest/dist/vue.min.js"></script>
<script src="//unpkg.com/bootstrap-vue@latest/dist/bootstrap-vue.min.js"></script>
<!-- Load the following for BootstrapVueIcons support -->
<script src="//unpkg.com/bootstrap-vue@latest/dist/bootstrap-vue-icons.min.js"></script>
</head>
<body>
<div id="app">
<b-dropdown id="dropdown-1" text="Dropdown Button" class="m-md-2">
<b-dropdown-item
v-for="(item,index) in menu"
:key="index"
@mouseover.native="toogleItem(index)"
@mouseout.native="toogleItem(index)">
<span>{{item.title}} <b-icon-caret-down-fill :scale="0.6" v-if="item.children"></b-icon-caret-down-fill></span>
<div v-if="item.children" class="sub-menu" v-show="item.showSubMenu">
<b-dropdown-item v-for="(item,index) in item.children" :key="index">{{item.title}}
</b-dropdown-item>
</div>
</b-dropdown-item>
</b-dropdown>
</div>
</body>
</html>