React class clock代码实例-前端--易笔记

React class clock代码实例

<html>
  <head>
      <title>Document</title>
      <script src="../react.js"></script>
      <script src="../react-dom.js"></script>
      <script src="https://cdn.bootcss.com/babel-core/5.8.38/browser.min.js"></script>
  </head>

  <body>
    <p id="demo"></p>
    <script type="text/babel">
       function FormatedDate(props) {
         return <h2>It is {props.date.toLocaleTimeString()}.</h2>
       }
       class Clock extends React.Component{
         constructor(props) {
           super(props)
           this.state = {date: new Date()}
         }

         componentDidMount() {
           this.timerID = setInterval(
             () => this.tick(),
             1000
           )
         }

         componentWillUnmount() {
           clearInterval(this.timerID)
         }

         tick() {
           this.setState({
             date: new Date()
           })
         }

         render() {
           return (
             <FormatedDate date={this.state.date} />
           )
         }
       }

       ReactDOM.render(
           <Clock />,
           document.getElementById("demo")
       )
    </script>
  </body>
</html>

时间：2017/11/18 11:13:00

React class clock代码实例