react做简单的todolist
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="https://cdn.staticfile.org/react/16.4.0/umd/react.development.js"></script>
    <script src="https://cdn.staticfile.org/react-dom/16.4.0/umd/react-dom.development.js"></script>
    <script src="https://cdn.staticfile.org/babel-standalone/6.26.0/babel.min.js"></script>
    <script src="https://unpkg.com/prop-types@15.6/prop-types.js"></script>
</head>
<body>
    <div id="example"></div>
    <script type="text/babel">
            class App extends React.Component{
                constructor(props){
                    super(props)
                    this.state = {
                        todos:['111','222','333']
                    }
                    this.addTodo = this.addTodo.bind(this)
                }
                // 01父组件定义函数
                addTodo(todo){
                    const {todos}=this.state
                    todos.unshift(todo)
                    // // 更新
                    this.setState({todos})
                }
                
                render(){
                    return(
                        <div>
                          <h1>simple todolist</h1>
                          <Add count={this.state.todos.length} addTodo={this.addTodo}/>
                          <List todos={this.state.todos}/>
                        </div>
                    )
                }
            }

            class Add extends React.Component{
                constructor(props){
                    super(props)
                    this.add = this.add.bind(this)
                }
                add(){
                    // 1.读取输入的数据
                    const todo = this.todoinput.value.trim()
                    // 2.检查合法性
                    if(todo==''){
                        return
                    }
                    // 3.添加
                    this.props.addTodo(todo)
                }
                render(){
                    return(
                        <div>
                         <input type="text" ref={input=>this.todoinput = input}/>
                        <button onClick={this.add}>add #{this.props.count+1}</button>
                        </div>
                    )
                }
            }
            Add.propTypes={
                count:PropTypes.number.isRequired,
                addTodo:PropTypes.func.isRequired
            }
    

            class List extends React.Component{
                
                render(){
                    const {todos} = this.props
                    // console.log( this.props.todos)
                    return(
                        <ul>
                           {
                             todos.map((todo,index)=><li key={index}>{todo}</li>)
                           }
                        </ul>
                    )
                }
            }
            List.propTypes={
                todos:PropTypes.array.isRequired
            }
            ReactDOM.render(<App/>,document.getElementById('example'))
    </script>
</body>
</html>
效果

Video_2020-10-11_121101.gif