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

order	title
9	zh-CN en-US 加载中状态 Loading

zh-CN

添加 loading 属性即可让按钮处于加载状态，最后两个按钮演示点击后进入加载状态。

en-US

A loading indicator can be added to a button by setting the loading property on the Dropdown.Button.

import { Menu, Dropdown, Space } from 'antd';
import { DownOutlined } from '@ant-design/icons';

const menu = (
  <Menu>
    <Menu.Item key="1">Submit and continue</Menu.Item>
  </Menu>
);
class App extends React.Component {
  state = {
    loadings: [],
  };

  enterLoading = index => {
    const newLoadings = [...this.state.loadings];
    newLoadings[index] = true;
    this.setState({
      loadings: newLoadings,
    });
    setTimeout(() => {
      newLoadings[index] = false;
      this.setState({ loadings: newLoadings });
    }, 6000);
  };

  render() {
    const { loadings } = this.state;
    return (
      <Space direction="vertical">
        <Dropdown.Button type="primary" loading overlay={menu}>
          Submit
        </Dropdown.Button>
        <Dropdown.Button type="primary" size="small" loading overlay={menu}>
          Submit
        </Dropdown.Button>
        <Dropdown.Button
          type="primary"
          loading={loadings[0]}
          overlay={menu}
          onClick={() => this.enterLoading(0)}
        >
          Submit
        </Dropdown.Button>
        <Dropdown.Button
          icon={<DownOutlined />}
          loading={loadings[1]}
          overlay={menu}
          onClick={() => this.enterLoading(1)}
        >
          Submit
        </Dropdown.Button>
      </Space>
    );
  }
}
ReactDOM.render(<App />, mountNode);