# 下拉菜单 Dropdown
当你想触发一些操作的时候。

## 演示
```demo
basic
trigger
cascade
placement
width
size
manual-position
```

## Props
|名称|类型|默认值|说明|
|-|-|-|-|
|size|`'small'\|'medium'\|'large'\|'huge'`|`large`||
|default-focus|`boolean`|`false`||
|options|`Array`|`[]`||
|trigger|`'hover' \| 'trigger' \| 'manual'`|`'hover'`||
|delay|`number`|`0`||
|duration|`number`|`300`||
|placement|`'top-start' \| 'top' \| 'top-end' \| 'right-start' \| 'right' \| 'right-end' \| 'bottom-start' \| 'bottom' \| 'bottom-end' \| 'left-start' \| 'left' \| 'left-end' \| `|`'bottom'`||
|arrow|`boolean`|`false`||
|disabled|`boolean`|`false`||
|manually-positioned|`boolean`|`false`||
|x|`number`|`null`||
|y|`number`|`null`||
|filp|`boolean`|`true`||
|controller|`object`|`null`||

## Events
|名称|参数|说明|
|-|-|-|
|select|`(selectedKey: string \| number)`||