react怎么实现五星评价

.star{
    display: inline-block;
}.star>span{
    display: inline-block;
    width: 10px;
    height: 10px;
    background-size: 10px 10px;
}.star0{
    background-image: url(img/star0.png);
}.star1{
    background-image: url(img/star1.png);
}.star2{
    background-image: url(img/star2.png);
}

import React,{Component} from 'react'class Star extends Component{
    constructor(props){
        super(props);        this.state={
            starNum:['star0','star0','star0','star0','star0'] //设置默认背景图        }
    }
    componentDidMount(){        this.getStar(Math.round(this.props.star)/2+1); //将传过来的类似7.3数字进行四舍五入再除2，得到的是类似2,3.5,6这种值    }
    getStar(num){
        let newStar = this.state.starNum.map((item)=>{ //当num=3.5时遍历后newStar数组变成['star2','star2','star2','star1','star0','star0']
            --num;            return num>=1?'star2':((num>0)?'star1':'star0'); //两次三目运算        })        this.setState({
            starNum:newStar  //设置state为遍历后的新数组        })
    }
    render(){        return (<span className="star">
            {                this.state.starNum.map((item, index)=>{                    return <span className={item} key={index}></span>                })
            }        </span>)    }
}
export default Star;

.newstar ul{
    background-image: url(component/img/ico.png);
}.newstar ul li{
    height: 60px;
    background: url(component/img/ico.png) left -62px;
}

import React,{Component} from 'react'class Star extends Component{
    render(){
        let num=(Math.round(this.props.star)/2)*20+'%'; //根据评分计算子元素的宽度
        return (<div className="newstar">
            <ul>
                <li style={{width:num}}></li>
            </ul>
        </div>)    }
}
export default Star;