lovecoding
/
VIP32


			
				
					
						
						
							1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253
							<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./babel.min.js"></script>
    <script src="./react.development.js"></script>
    <script src="./react-dom.development.js"></script>
</head>
<body>
    <div id="root"></div>
    <script type="text/babel">
        const root = ReactDOM.createRoot(document.getElementById("root"));
        function App() {
            // import {router} from  'useRouter'
            // ref绑定 
            // 1.在定义部分 声明 ref名字 来自于 React.createRef()里
            // 2.在元素部分  需要使用ref={名字}
            // 返出类型：{current:绑定的ref元素}
            const countRef = React.createRef();
            const inpRef = React.createRef();
            function getMain() {
                console.log("走进来")
                console.log(countRef,'countRef');
                console.log(inpRef,'inpRef');
            }
            return (
                <div>
                    <p onClick={getMain}>哈哈哈</p>
                    <Count  ref={countRef}/>
                    <input type="text" ref={inpRef} />
                </div>
            )
        }
        class Count extends React.Component {
            constructor() {
                super();
                this.state= {
                    a:"1",
                    b:"你好"
                }
            }
            render() {
                return (
                    <h1>我是一个计数器</h1>
                )
            }
        }
        root.render(<App/>)
    </script>
</body>
</html>