ref可用来获取组件标签的dom节点，给组件标签绑定ref，组件的实例对象上有个属性叫做refs，组件标签上绑的ref值就会显示在refs中
<!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>字符串形式的ref</title>
</head>
<body>
<div id="test"></div>
<script crossorigin src="https://unpkg.com/react@16/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
<script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>
<script src="https://cdn.staticfile.org/prop-types/15.6.1/prop-types.js"></script>
<script type="text/babel">
class Demo extends React.Component {
render() {
return (
// 给组件标签绑定ref，组件的实例对象上有个属性叫做refs，组件标签上绑的ref值就会显示在refs中
<div>
<input ref="input1" type="text" placeholder="点击右侧提示数据" />
<button onClick={ this.clickData }>点击提示左侧输入的数据</button>
<input ref="input2" type="text" placeholder="失焦后提示数据" onBlur={ this.blurData }/>
</div>
)
}
clickData = () => {
const { input1 } = this.refs
alert(input1.value)
}
blurData = () => {
const { input2 } = this.refs
alert(input2.value);
}
}
ReactDOM.render(<Demo />, document.getElementById('test'))
</script>
</body>
</html>
