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@@ -0,0 +1,57 @@
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+<!DOCTYPE html>
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+<html lang="en">
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+
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+<head>
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+ <meta charset="UTF-8">
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+ <meta name="viewport" content="width=device-width, initial-scale=1.0">
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+ <title>Document</title>
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+ <script src="./babel.min.js"></script>
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+ <script src="./react.development.js"></script>
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+ <script src="./react-dom.development.js"></script>
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+</head>
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+
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+<body>
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+ <div id="root"></div>
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+ <script type="text/babel">
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+ /**
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+ * ref绑定
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+ * 1.在定义部分 声明ref的名字 来自于React.createRef()
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+ * 2.在jsx部分 使用 ref={xxxx}
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+ * 3.输出 {current:绑定的ref元素}
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+ */
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+ let root = ReactDOM.createRoot(document.getElementById("root"));
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+ let countRef = React.createRef();
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+ let inpRef = React.createRef();
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+ function App() {
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+ function handleClick() {
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+ console.log(countRef)
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+ console.log(inpRef)
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+ }
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+ return (
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+ <div>
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+ <Count ref={countRef} />
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+ <button onClick={handleClick}>哈哈哈</button>
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+ <input type="text" ref={inpRef} />
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+ </div>
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+ )
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+ }
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+ class Count extends React.Component {
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+ constructor(props) {
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+ super(props);
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+ this.state = {
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+ aa: 20
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+ }
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+ }
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+ render() {
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+ return (
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+ <div>
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+ {this.state.aa}
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+ </div>
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+ )
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+ }
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+ }
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+ root.render(<App/>);
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+ </script>
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+</body>
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+
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+</html>
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zheng