lovecoding
/
W250511


			
				
					
						
						
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							<!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">
        let root = ReactDOM.createRoot(document.getElementById("root"));
        function App() {
            return (
                <div>
                    <Flower />
                </div>
            )
        }
        class Flower extends React.Component {
            constructor(props) {
                super(props);
                this.state = {
                    currentTime: new Date(),
                    count: 0
                }
            }
            // 挂载
            componentDidMount() {
                console.log("挂载");
                this.timer = setInterval(() => {
                    this.setState((state, props) => ({
                        currentTime: new Date(),
                        count: 2
                    }))
                }, 1000)
            }
            // 更新
            componentDidUpdate() {
                console.log("更新")
            }
            // 卸载
            componentWillUnMount() {
                clearInterval(this.timer);
            }
            render() {
                return (
                    <div>
                        <h1>类组件</h1>
                        <h2>{this.state.count}</h2>
                        <h3>{this.state.currentTime.toLocaleString()}</h3>
                    </div>
                )
            }
        }
        root.render(<App />);
    </script>
</body>

</html>