ant-design/components/dropdown/demo/placement.md

order	title
1	zh-CN en-US 弹出位置 Placement

zh-CN

支持 6 个弹出位置。

en-US

Support 6 placements.

import { Menu, Dropdown, Button, Space } from 'antd';

const menu = (
  <Menu>
    <Menu.Item>
      <a target="_blank" rel="noopener noreferrer" href="http://www.alipay.com/">
        1st menu item
      </a>
    </Menu.Item>
    <Menu.Item>
      <a target="_blank" rel="noopener noreferrer" href="http://www.taobao.com/">
        2nd menu item
      </a>
    </Menu.Item>
    <Menu.Item>
      <a target="_blank" rel="noopener noreferrer" href="http://www.tmall.com/">
        3rd menu item
      </a>
    </Menu.Item>
  </Menu>
);

ReactDOM.render(
  <Space direction="vertical">
    <Space wrap>
      <Dropdown overlay={menu} placement="bottomLeft">
        <Button>bottomLeft</Button>
      </Dropdown>
      <Dropdown overlay={menu} placement="bottomCenter">
        <Button>bottomCenter</Button>
      </Dropdown>
      <Dropdown overlay={menu} placement="bottomRight">
        <Button>bottomRight</Button>
      </Dropdown>
    </Space>
    <Space wrap>
      <Dropdown overlay={menu} placement="topLeft">
        <Button>topLeft</Button>
      </Dropdown>
      <Dropdown overlay={menu} placement="topCenter">
        <Button>topCenter</Button>
      </Dropdown>
      <Dropdown overlay={menu} placement="topRight">
        <Button>topRight</Button>
      </Dropdown>
    </Space>
  </Space>,
  mountNode,
);