Bootstrap 下拉菜单（Dropdowns）

本章将重点介绍 Bootstrap 下拉菜单。下拉菜单是可切换的，是以列表格式显示链接的上下文菜单。这可以通过与 下拉菜单（Dropdown） JavaScript 插件 的互动来实现。

如需使用下拉菜单，只需要在 class .dropdown 内加上下拉菜单即可。下面的实例演示了基本的下拉菜单：

实例

< 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 = " # " > Java </ a > </ li > < li role = " presentation " > < a role = " menuitem " tabindex = " -1 " href = " # " > 数据挖掘 </ a > </ li > < li role = " presentation " > < a role = " menuitem " tabindex = " -1 " href = " # " > 数据通信/网络 </ a > </ li > < li role = " presentation " class = " divider " > </ li > < li role = " presentation " > < a role = " menuitem " tabindex = " -1 " href = " # " > 分离的链接 </ a > </ li > </ ul > </ div >

尝试一下 »

结果如下所示：

基本的下拉菜单（Dropdowns）

选项

对齐

通过向 .dropdown-menu 添加 class .pull-right 来向右对齐下拉菜单。下面的实例演示了这点：

实例

< 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 pull-right " role = " menu " aria-labelledby = " dropdownMenu1 " > < li role = " presentation " > < a role = " menuitem " tabindex = " -1 " href = " # " > Java </ a > </ li > < li role = " presentation " > < a role = " menuitem " tabindex = " -1 " href = " # " > 数据挖掘 </ a > </ li > < li role = " presentation " > < a role = " menuitem " tabindex = " -1 " href = " # " > 数据通信/网络 </ a > </ li > < li role = " presentation " class = " divider " > </ li > < li role = " presentation " > < a role = " menuitem " tabindex = " -1 " href = " # " > 分离的链接 </ a > </ li > </ ul > </ div >

尝试一下 »

结果如下所示：

向右对齐下拉菜单

标题

您可以使用 class dropdown-header 向下拉菜单的标签区域添加标题。下面的实例演示了这点：

实例

< 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 " class = " dropdown-header " > 下拉菜单标题 </ li > < li role = " presentation " > < a role = " menuitem " tabindex = " -1 " href = " # " > Java </ a > </ li > < li role = " presentation " > < a role = " menuitem " tabindex = " -1 " href = " # " > 数据挖掘 </ a > </ li > < li role = " presentation " > < a role = " menuitem " tabindex = " -1 " href = " # " > 数据通信/网络 </ a > </ li > < li role = " presentation " class = " divider " > </ li > < li role = " presentation " class = " dropdown-header " > 下拉菜单标题 </ li > < li role = " presentation " > < a role = " menuitem " tabindex = " -1 " href = " # " > 分离的链接 </ a > </ li > </ ul > </ div >

尝试一下 »

结果如下所示：

下拉菜单标题

更多实例

类 描述 实例
.dropdown 指定下拉菜单，下拉菜单都包裹在 .dropdown 里 尝试一下
.dropdown-menu 创建下拉菜单 尝试一下
.dropdown-menu-right 下拉菜单右对齐 尝试一下
.dropdown-header 下拉菜单中添加标题 尝试一下
.dropup 指定向上弹出的下拉菜单 尝试一下
.disabled 下拉菜单中的禁用项 尝试一下
.divider 下拉菜单中的分割线 尝试一下