什么是 Uncaught TypeError：無法讀取 AppBar + Drawer 組件（ReactJS + Material-UI）未定義的屬性“打開”？

Question

我正在嘗試從 Material-UI 框架中獲取導航、AppBar（ http://www.material-ui.com/#/components/app-bar ）左側的默認漢堡圖標，以在單擊時滑動打開 Drawer 組件（ http://www.material-ui.com/#/components/drawer ）。 但是一旦點擊，我就會收到以下錯誤，我無法弄清楚：

未捕獲的類型錯誤：無法讀取未定義的屬性“打開”

任何有關它的見解或指導將不勝感激。 提前謝謝你。

import React, { Component } from 'react'
import { Drawer, AppBar, MenuItem} from 'material-ui'
import baseTheme from 'material-ui/styles/baseThemes/lightBaseTheme'
import getMuiTheme from 'material-ui/styles/getMuiTheme'
import { Route, Router } from 'react-router'



export default class Main extends Component  {

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

  getChildContext() {
    return {muiTheme: getMuiTheme(baseTheme)};
  }

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

        render() {
            return (
                <div>
                <AppBar   
                  isInitiallyOpen={true} 
                  onLeftIconButtonTouchTap={this.handleToggle}        
                  onLeftIconButtonClick={this.handleToggle} 
                />

                <Drawer
                  docked={false}
                  open={this.state.open}>
                  <MenuItem>Menu Item 1</MenuItem>
                  <MenuItem>Menu Item 2</MenuItem>
                  <MenuItem>Menu Item 3</MenuItem>
                </Drawer>
                </div>
            );
        }
    }

export default Main;

Answer 1

您還可以制作功能組件而不是類組件。它將使您的組件清晰易讀 -

import React, { useState } from 'react'
import { Drawer, AppBar, MenuItem } from 'material-ui'
import baseTheme from 'material-ui/styles/baseThemes/lightBaseTheme'
import getMuiTheme from 'material-ui/styles/getMuiTheme'
import { Route, Router } from 'react-router'



export default function Main(props) {

    let [open, setOpen] = useState(false);

    let handleToggle = () => {
        setOpen(!open);
    }

    return (
        <div>
            <AppBar
                isInitiallyOpen={true}
                onLeftIconButtonTouchTap={handleToggle}
                onLeftIconButtonClick={handleToggle}
            />

            <Drawer
                docked={false}
                open={open}>
                <MenuItem>Menu Item 1</MenuItem>
                <MenuItem>Menu Item 2</MenuItem>
                <MenuItem>Menu Item 3</MenuItem>
            </Drawer>
        </div>
    );
}