看代碼class Background extends React.Component{    constructor(opts) {        super(opts);        this.initStatus();     }     initStatus() {        this.state = {            effect: false         }     }     render(){        this.initStatus();        return <div className={cs({background: true, effect: this.state.effect})}>             <div className="background-pannel">                 <div className="background-image-back"></div>             </div>             <div className="background-pannel">                 <div className="background-image"></div>             </div>         </div>     }          componentDidMount() {        this.setState({effect: true}, ()=>{            console.log(this.state.effect);         })     } }export { Background }為什么沒有效果，打印出來的effect值依然是false？