react/basic/2/P04.html

<!--
 * @Author: chenxuan
 * @Date: 2022-01-02 23:49:08
 * @LastEditTime: 2022-03-20 18:20:28
 * @LastEditors: chenxuan
-->
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>createRef</title>
    <script src="../package/old/react.development.js"></script>
    <script src="../package/old/react-dom.development.js"></script>
    <script src="../package/old/babel.min.js"></script>
</head>
<body>
    <div id="app"></div>
    <script type="text/babel">
        class Demo extends React.Component{
            myef=React.createRef();
            getValue=()=>{
                console.log(this.myef)
                alert(this.myef.current.value)
            }
            render(){
                return(
                    <div>
                        <input type="text" ref={this.myef}/>
                        <button onClick={this.getValue}>更新</button>
                    </div>
                )
            }
        }
        ReactDOM.render(
            <Demo/>,document.getElementById('app')
        )
    </script>
    <!-- 该容器专人专用，只能存1个 -->
</body>
</html>