javascript - 类型错误 : React object is undefined on createElement

Question

我是 React 和 Material UI 的新手，我正在尝试创建一个带有 Tabs 的 AppBar 作为 children 。我当前的实现如下所示:

import {React, PropTypes, Component} from 'react';
import TodoTextInput from './TodoTextInput';
import injectTapEventPlugin from 'react-tap-event-plugin';
import baseTheme from 'material-ui/styles/baseThemes/lightBaseTheme'
import getMuiTheme from 'material-ui/styles/getMuiTheme'
import {Tabs, Tab} from 'material-ui/Tabs';
import {AppBar} from 'material-ui/AppBar';

const styles = {
  headline: {
    fontSize: 24,
    paddingTop: 16,
    marginBottom: 12,
    fontWeight: 400
  }
};

function handleActive(tab) {
  alert(`A tab with this route property ${tab.props['data-route']} was activated.`);
}
const defaultStyle = {
  marginLeft: 20
};

class Header extends Component {
  render() {
    return (
      <header className="header">
      <AppBar title="TEST" />
        <Tabs>
          <Tab label="Tab 1" >
            <div>

            </div>
          </Tab>
          <Tab label="Tab 2" >
            <div>

            </div>
          </Tab>
          <Tab label="Tab 3" >
            <div>

            </div>
          </Tab>
          <Tab label="Tab 4" >
            <div>

            </div>
          </Tab>
        </Tabs>
        {children}
      </header>
    );
  }
}

module.exports = Header;

我收到一条错误消息:

TypeError: undefined is not an object (evaluating '_react.React.createElement')

我不确定如何解决这个问题。请帮忙!

Answer 1

你错误地导入了 React，不过你已经接近了。改成

从 'react' 导入 React, { PropTypes, Component };

将 React 视为父项，将其他项视为子项。您也可以只导入 React 并使用 React.PropTypes 和 React.Component 访问另一个。