使用 Appbar + Drawer 时遇到问题（Material UI + ReactJS）

我正在尝试使用 ReactJS + Material UI 制作我的第一个应用程序，但没有成功。

我唯一想做的就是，当我单击栏上的按钮时，显示左侧抽屉。

我有以下代码（App.jsx）：

import React from 'react';
import MuiThemeProvider from 'material-ui/styles/MuiThemeProvider';
import getMuiTheme from 'material-ui/styles/getMuiTheme';
import lightBaseTheme from 'material-ui/styles/baseThemes/lightBaseTheme';
import AppBar from 'material-ui/AppBar';
import LeftDrawer from './LeftDrawer.jsx';


class App extends React.Component {

    constructor(props) {
        super(props);
        this.state = {open: false};
    }

    handleTouchMap() {
        this.setState({open: !this.state.open});
    }

    render() {
        return (
            <MuiThemeProvider muiTheme={getMuiTheme(lightBaseTheme)}>
                <div>
                    <AppBar
                    title = { "Test 1" }
                    onLeftIconButtonTouchTap={this.handleTouchMap.bind(this)}
                />
                    <LeftDrawer open={this.state.open} />
                </div>
            </MuiThemeProvider>  
        );
    }
}

export default App;

接下来（LeftDrawer.jsx）：

import React from 'react';
import Drawer from 'material-ui/Drawer';
import MenuItem from 'material-ui/MenuItem';


class LeftDrawer extends React.Component {

    constructor(props) {
        super(props);
    }

    render() {
        return (
            <div> 
                <Drawer open={this.state.open}>
                    <MenuItem>Menu Item 1</MenuItem>
                    <MenuItem>Menu Item 2</MenuItem>
                </Drawer>
            </div>
        );
    }
}

export default LeftDrawer;

我总是得到这样的信息：

Warning: Failed prop type: Invalid prop `children` supplied to `MuiThemeProvider`, expected a single ReactElement.
    in MuiThemeProvider (created by App)
    in App

Uncaught Invariant Violation: MuiThemeProvider.render(): 
A valid React element (or null) must be returned. You may have returned undefined, an array or some other invalid object.

你知道我做错了什么吗？请！

如果我放一个<div>包裹<Appbar> and <Leftdrawer>在 App.jsx 中。它解决了 MuiThemeProvider 错误。 但现在，我收到以下错误：

Uncaught TypeError: Cannot read property 'open' of null

您应该将抽屉的打开状态存储在App组件的状态，并将其作为 prop 传递给Drawer成分。

App.jsx:

class MatApp extends React.Component {
  constructor(props) {
    super(props);
    this.state = {open: false};
  }

  handleTouchMap() {
    this.setState({open: !this.state.open});
  }

  render() {
    return (
      <MuiThemeProvider muiTheme={getMuiTheme(lightBaseTheme)}>
        <AppBar
          title = { "Test 1" }
          onLeftIconButtonTouchTap = { this.handleTouchMap.bind(this) }
        />
        <LeftDrawer open={this.state.open} />
      </MuiThemeProvider>  

    );
  }

}
export default App;

左抽屉.jsx:

class LeftDrawer extends React.Component {

  constructor(props) {
    super(props);
  }

  render() {
    return (
      <div>
        <Drawer open={this.props.open}>
          <MenuItem>Menu Item</MenuItem>
          <MenuItem>Menu Item 2</MenuItem>
        </Drawer>
      </div>
    );
  }
}
export default LeftDrawer;