react倒计时
export default class TimerTest extends Component{ constructor(props) { super(props); this.state = { seconds:0 }; } tick(){ this.setState(preState =>({ seconds:preState.seconds+1 })); } componentDidMount() { this.interval = setInterval(() => this.tick(), 1000); } componentWillUnmount() { clearInterval(this.interval); } render(){ return( <div> Seconds:{this.state.seconds} </div> ); } }
今日事今日毕