ant-design/components/tree-select/demo/placement.md

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

zh-CN

可以通过 placement 手动指定弹出的位置。

en-US

You can manually specify the position of the popup via placement.

import React, { useState } from 'react';
import { TreeSelect, Radio } from 'antd';

const { TreeNode } = TreeSelect;

const Demo = () => {
  const [placement, SetPlacement] = useState('topLeft');

  const placementChange = e => {
    SetPlacement(e.target.value);
  };

  return (
    <>
      <Radio.Group value={placement} onChange={placementChange}>
        <Radio.Button value="topLeft">topLeft</Radio.Button>
        <Radio.Button value="topRight">topRight</Radio.Button>
        <Radio.Button value="bottomLeft">bottomLeft</Radio.Button>
        <Radio.Button value="bottomRight">bottomRight</Radio.Button>
      </Radio.Group>
      <br />
      <br />

      <TreeSelect
        showSearch
        dropdownStyle={{ maxHeight: 400, overflow: 'auto', minWidth: 300 }}
        placeholder="Please select"
        dropdownMatchSelectWidth={false}
        placement={placement}
        allowClear
        treeDefaultExpandAll
      >
        <TreeNode value="parent 1" title="parent 1">
          <TreeNode value="parent 1-0" title="parent 1-0">
            <TreeNode value="leaf1" title="leaf1" />
            <TreeNode value="leaf2" title="leaf2" />
          </TreeNode>
          <TreeNode value="parent 1-1" title="parent 1-1">
            <TreeNode value="leaf3" title={<b style={{ color: '#08c' }}>leaf3</b>} />
          </TreeNode>
        </TreeNode>
      </TreeSelect>
    </>
  );
};

ReactDOM.render(<Demo />, mountNode);