react分頁顯示數據的方法

const listData = [{
    key:"001",
    idd:"001",
    title:"webstorm連接github，方便的管理倉庫",
    time:"2016-12-01",
    tag:" git ",
    contents:"66666666666666！"
}] //等等等多條數據

class listBox extends Component {

    constructor(props){
        super(props);
        this.pageNext=this.pageNext.bind(this);
        this.setPage=this.setPage.bind(this);
        this.state = {
            indexList:[],//當前渲染的頁面數據
            totalData:listData,
            current: 1, //當前頁碼
            pageSize:4, //每頁顯示的條數
            goValue:0,  //要去的條數index
            totalPage:0,//總頁數
        };

    }

    componentWillMount(){
        //設置總頁數
        this.setState({
            totalPage:Math.ceil( this.state.totalData.length/this.state.pageSize),
        })
        this.pageNext(this.state.goValue)

    }

    //設置內容
    setPage(num){
        this.setState({
            indexList:this.state.totalData.slice(num,num+this.state.pageSize)
        })
    }


    pageNext (num) {
        this.setPage(num)
    }



    render() {

        return (
            <div className="main">
                <div className="top_bar">
                </div>
                <div className="lists">
                    <ul className="index">
                        {this.state.indexList.map(function (cont) {
                            return <List {...cont} />
                        })}
                    </ul>

                    <PageButton { ...this.state } pageNext={this.pageNext} />

                </div>
            </div>
        );
    }
}

class list extends Component {
    constructor(props) {
        super(props);
    }

    render() {
        const { idd,title,time,tag,contents } = this.props

        return (
            <li id={idd}>
                <Link to={`/list/listmore/${idd}`} >
                    <h3>{title}</h3>
                    <div className="icon">
                        <i className="fa fa-calendar"></i>
                        <span>發表於 {time} </span>
                        <i className="fa fa-sitemap"></i>
                        <span>分類於 {tag}  </span>
                        <i className="fa fa-edit"></i>
                        <span>暫無評論</span>
                    </div>
                    <p>{contents}</p>
                    <span className="more">more</span>
                </Link>
            </li>
        );
    }
}

class pageButton extends Component {

    constructor(props) {
        super(props);
        this.setNext=this.setNext.bind(this);
        this.setUp=this.setUp.bind(this);
        this.state={
            num: 0,
            pagenum:this.props.current
        }
    }

    //下一頁
    setNext(){
        if(this.state.pagenum < this.props.totalPage){
            this.setState({
                num:this.state.num + this.props.pageSize,
                pagenum:this.state.pagenum + 1
            },function () {
                console.log(this.state)
                this.props.pageNext(this.state.num)
            })
        }
    }

    //上一頁
    setUp(){
        if(this.state.pagenum > 1){
            this.setState({
                num:this.state.num - this.props.pageSize,
                pagenum:this.state.pagenum - 1
            },function () {
                console.log(this.state)
                this.props.pageNext(this.state.num)
            })
        }
    }

    render() {
        return (
            <div className="change_page">
                <span onClick={ this.setUp } >上一頁</span>
                <span>{ this.state.pagenum }頁/ { this.props.totalPage }頁</span>
                <span onClick={ this.setNext }>下一頁</span>
            </div>
        );
    }
}