Cascader级联选择

级联选择框。

何时使用

• 需要从一组相关联的数据集合进行选择，例如省市区，公司层级，事物分类等。

• 从一个较大的数据集合中进行选择时，用多级分类进行分隔，方便选择。

• 比起 Select 组件，可以在同一个浮层中完成选择，有较好的体验。

代码演示

基本

省市区级联。

import { Cascader } from 'antd';
const options = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    children: [
      {
        value: 'hangzhou',
        label: 'Hangzhou',
        children: [
          {
            value: 'xihu',
            label: 'West Lake',
          },
        ],
      },
    ],
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    children: [
      {
        value: 'nanjing',
        label: 'Nanjing',
        children: [
          {
            value: 'zhonghuamen',
            label: 'Zhong Hua Men',
          },
        ],
      },
    ],
  },
];
function onChange(value) {
  console.log(value);
}
ReactDOM.render(
  <Cascader options={options} onChange={onChange} placeholder="Please select" />,
  mountNode,
);

可以自定义显示

切换按钮和结果分开。

import { Cascader } from 'antd';
const options = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    children: [
      {
        value: 'hangzhou',
        label: 'Hangzhou',
      },
    ],
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    children: [
      {
        value: 'nanjing',
        label: 'Nanjing',
      },
    ],
  },
];
class CitySwitcher extends React.Component {
  state = {
    text: 'Unselect',
  };
  onChange = (value, selectedOptions) => {
    this.setState({
      text: selectedOptions.map(o => o.label).join(', '),
    });
  };
  render() {
    return (
      <span>
        {this.state.text}
        &nbsp;
        <Cascader options={options} onChange={this.onChange}>
          <a href="#">Change city</a>
        </Cascader>
      </span>
    );
  }
}
ReactDOM.render(<CitySwitcher />, mountNode);

禁用选项

通过指定 options 里的 disabled 字段。

import { Cascader } from 'antd';
const options = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    children: [
      {
        value: 'hangzhou',
        label: 'Hangzhou',
        children: [
          {
            value: 'xihu',
            label: 'West Lake',
          },
        ],
      },
    ],
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    disabled: true,
    children: [
      {
        value: 'nanjing',
        label: 'Nanjing',
        children: [
          {
            value: 'zhonghuamen',
            label: 'Zhong Hua Men',
          },
        ],
      },
    ],
  },
];
function onChange(value) {
  console.log(value);
}
ReactDOM.render(<Cascader options={options} onChange={onChange} />, mountNode);

大小

不同大小的级联选择器。

import { Cascader } from 'antd';
const options = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    children: [
      {
        value: 'hangzhou',
        label: 'Hangzhou',
        children: [
          {
            value: 'xihu',
            label: 'West Lake',
          },
        ],
      },
    ],
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    children: [
      {
        value: 'nanjing',
        label: 'Nanjing',
        children: [
          {
            value: 'zhonghuamen',
            label: 'Zhong Hua Men',
          },
        ],
      },
    ],
  },
];
function onChange(value) {
  console.log(value);
}
ReactDOM.render(
  <>
    <Cascader size="large" options={options} onChange={onChange} />
    <br />
    <br />
    <Cascader options={options} onChange={onChange} />
    <br />
    <br />
    <Cascader size="small" options={options} onChange={onChange} />
    <br />
    <br />
  </>,
  mountNode,
);

搜索

可以直接搜索选项并选择。

Cascader[showSearch] 暂不支持服务端搜索，更多信息见 #5547

import { Cascader } from 'antd';
const options = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    children: [
      {
        value: 'hangzhou',
        label: 'Hangzhou',
        children: [
          {
            value: 'xihu',
            label: 'West Lake',
          },
          {
            value: 'xiasha',
            label: 'Xia Sha',
            disabled: true,
          },
        ],
      },
    ],
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    children: [
      {
        value: 'nanjing',
        label: 'Nanjing',
        children: [
          {
            value: 'zhonghuamen',
            label: 'Zhong Hua men',
          },
        ],
      },
    ],
  },
];
function onChange(value, selectedOptions) {
  console.log(value, selectedOptions);
}
function filter(inputValue, path) {
  return path.some(option => option.label.toLowerCase().indexOf(inputValue.toLowerCase()) > -1);
}
ReactDOM.render(
  <Cascader
    options={options}
    onChange={onChange}
    placeholder="Please select"
    showSearch={{ filter }}
  />,
  mountNode,
);

自定义字段名

自定义字段名。

import { Cascader } from 'antd';
const options = [
  {
    code: 'zhejiang',
    name: 'Zhejiang',
    items: [
      {
        code: 'hangzhou',
        name: 'Hangzhou',
        items: [
          {
            code: 'xihu',
            name: 'West Lake',
          },
        ],
      },
    ],
  },
  {
    code: 'jiangsu',
    name: 'Jiangsu',
    items: [
      {
        code: 'nanjing',
        name: 'Nanjing',
        items: [
          {
            code: 'zhonghuamen',
            name: 'Zhong Hua Men',
          },
        ],
      },
    ],
  },
];
function onChange(value) {
  console.log(value);
}
ReactDOM.render(
  <Cascader
    fieldNames={{ label: 'name', value: 'code', children: 'items' }}
    options={options}
    onChange={onChange}
    placeholder="Please select"
  />,
  mountNode,
);

默认值

默认值通过数组的方式指定。

import { Cascader } from 'antd';
const options = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    children: [
      {
        value: 'hangzhou',
        label: 'Hangzhou',
        children: [
          {
            value: 'xihu',
            label: 'West Lake',
          },
        ],
      },
    ],
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    children: [
      {
        value: 'nanjing',
        label: 'Nanjing',
        children: [
          {
            value: 'zhonghuamen',
            label: 'Zhong Hua Men',
          },
        ],
      },
    ],
  },
];
function onChange(value) {
  console.log(value);
}
ReactDOM.render(
  <Cascader
    defaultValue={['zhejiang', 'hangzhou', 'xihu']}
    options={options}
    onChange={onChange}
  />,
  mountNode,
);

移入展开

通过移入展开下级菜单，点击完成选择。

import { Cascader } from 'antd';
const options = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    children: [
      {
        value: 'hangzhou',
        label: 'Hangzhou',
        children: [
          {
            value: 'xihu',
            label: 'West Lake',
          },
        ],
      },
    ],
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    children: [
      {
        value: 'nanjing',
        label: 'Nanjing',
        children: [
          {
            value: 'zhonghuamen',
            label: 'Zhong Hua Men',
          },
        ],
      },
    ],
  },
];
function onChange(value) {
  console.log(value);
}
// Just show the latest item.
function displayRender(label) {
  return label[label.length - 1];
}
ReactDOM.render(
  <Cascader
    options={options}
    expandTrigger="hover"
    displayRender={displayRender}
    onChange={onChange}
  />,
  mountNode,
);

选择即改变

这种交互允许只选中父级选项。

import { Cascader } from 'antd';
const options = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    children: [
      {
        value: 'hangzhou',
        label: 'Hanzhou',
        children: [
          {
            value: 'xihu',
            label: 'West Lake',
          },
        ],
      },
    ],
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    children: [
      {
        value: 'nanjing',
        label: 'Nanjing',
        children: [
          {
            value: 'zhonghuamen',
            label: 'Zhong Hua Men',
          },
        ],
      },
    ],
  },
];
function onChange(value) {
  console.log(value);
}
ReactDOM.render(<Cascader options={options} onChange={onChange} changeOnSelect />, mountNode);

自定义已选项

例如给最后一项加上邮编链接。

import { Cascader } from 'antd';
const options = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    children: [
      {
        value: 'hangzhou',
        label: 'Hangzhou',
        children: [
          {
            value: 'xihu',
            label: 'West Lake',
            code: 752100,
          },
        ],
      },
    ],
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    children: [
      {
        value: 'nanjing',
        label: 'Nanjing',
        children: [
          {
            value: 'zhonghuamen',
            label: 'Zhong Hua Men',
            code: 453400,
          },
        ],
      },
    ],
  },
];
function handleAreaClick(e, label, option) {
  e.stopPropagation();
  console.log('clicked', label, option);
}
const displayRender = (labels, selectedOptions) =>
  labels.map((label, i) => {
    const option = selectedOptions[i];
    if (i === labels.length - 1) {
      return (
        <span key={option.value}>
          {label} (<a onClick={e => handleAreaClick(e, label, option)}>{option.code}</a>)
        </span>
      );
    }
    return <span key={option.value}>{label} / </span>;
  });
ReactDOM.render(
  <Cascader
    options={options}
    defaultValue={['zhejiang', 'hangzhou', 'xihu']}
    displayRender={displayRender}
    style={{ width: '100%' }}
  />,
  mountNode,
);

动态加载选项

使用 loadData 实现动态加载选项。

注意：loadData 与 showSearch 无法一起使用。

import { Cascader } from 'antd';
const optionLists = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    isLeaf: false,
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    isLeaf: false,
  },
];
const LazyOptions = () => {
  const [options, setOptions] = React.useState(optionLists);
  const onChange = (value, selectedOptions) => {
    console.log(value, selectedOptions);
  };
  const loadData = selectedOptions => {
    const targetOption = selectedOptions[selectedOptions.length - 1];
    targetOption.loading = true;
    // load options lazily
    setTimeout(() => {
      targetOption.loading = false;
      targetOption.children = [
        {
          label: `${targetOption.label} Dynamic 1`,
          value: 'dynamic1',
        },
        {
          label: `${targetOption.label} Dynamic 2`,
          value: 'dynamic2',
        },
      ];
      setOptions([...options]);
    }, 1000);
  };
  return <Cascader options={options} loadData={loadData} onChange={onChange} changeOnSelect />;
};
ReactDOM.render(<LazyOptions />, mountNode);

扩展菜单

使用 dropdownRender 对下拉菜单进行自由扩展。

import { Cascader, Divider } from 'antd';
const options = [
  {
    value: 'zhejiang',
    label: 'Zhejiang',
    children: [
      {
        value: 'hangzhou',
        label: 'Hangzhou',
        children: [
          {
            value: 'xihu',
            label: 'West Lake',
          },
        ],
      },
    ],
  },
  {
    value: 'jiangsu',
    label: 'Jiangsu',
    children: [
      {
        value: 'nanjing',
        label: 'Nanjing',
        children: [
          {
            value: 'zhonghuamen',
            label: 'Zhong Hua Men',
          },
        ],
      },
    ],
  },
];
function dropdownRender(menus) {
  return (
    <div>
      {menus}
      <Divider style={{ margin: 0 }} />
      <div style={{ padding: 8 }}>The footer is not very short.</div>
    </div>
  );
}
ReactDOM.render(
  <Cascader options={options} dropdownRender={dropdownRender} placeholder="Please select" />,
  mountNode,
);

API

<Cascader options={options} onChange={onChange} />

showSearch

showSearch 为对象时，其中的字段：

Option

interface Option {
  value: string | number;
  label?: React.ReactNode;
  disabled?: boolean;
  children?: Option[];
}

方法

注意，如果需要获得中国省市区数据，可以参考 china-division。