touchstart = this.touchStart.bind(this);
    touchmove = this.touchMove.bind(this);
    touchend = this.touchEnd.bind(this);
    //设置transform
    cssTransform(ele, attr, val){
        if(!ele.transform){
            ele.transform = {};
        };
        //当传入值时对属性进行设置。
        if(arguments.length > 2){
            ele.transform[attr] = val;
            var sval = '';
            for(var s in ele.transform){
                if(s === 'translateX'){
                    sval += s + '(' + ele.transform[s] + 'px)';
                }
                //如果实在不理解，可以console.log(sval)可以看到到最后一张时会有一个先跳到第二张再快速到第三张的过程
                ele.style.WebkitTransform = ele.style.transform = sval;
            }
        }
        else{
            val = ele.transform[attr];
            if(typeof val === 'undefined'){
                if(attr === 'translateX'){
                    val = 0;
                }
            };
            return val;
        }
    }
    //自动轮播
    auto(){
        clearInterval(this.timer);
        this.timer = setInterval(() => {
            //当到达最后一张时
            if(this.now === this.props.len - 1){
                this.now = this.props.len / 2 - 1;
                //这两句代码很重要，是实现的关键，none是为了不出现平移而是直接跳变
                this.LunBoEle.style.transition = 'none';
                this.cssTransform(this.LunBoEle, 'translateX', - this.now * this.sliderWidth);
            }
    //定时是为了tab函数中执行的csstransform函数与上面到达最后一张时的csstransform有先后，不然仍会导致右移；
            setTimeout(() => {
                this.now++;
                this.tab();
            }, 30);
        }, this.props.delay * 1000);
    }

    tab(){
        this.LunBoEle.style.transition = '.5s';
        this.cssTransform(this.LunBoEle, 'translateX', -this.now * this.sliderWidth);
        let SelectIndex = this.now % (this.props.len / 2);
        $('.slider-dots-wrap span').eq(SelectIndex).addClass('slider-dot-selected').siblings().removeClass('slider-dot-selected');
    }
    componentDidMount() {
        this.LunBoEle = document.querySelector('ul.lunbo');
        this.SliderEle = document.querySelector('.slider');
        this.sliderWidth = $('.slider').width();
        this.cssTransform(this.LunBoEle, 'translateX', 0);
        this.auto.bind(this)();
        this.SliderEle.addEventListener('touchstart', this.touchstart, false);
        this.SliderEle.addEventListener('touchmove', this.touchmove, false);
        this.SliderEle.addEventListener('touchend', this.touchend, false);
    }
//触发
    touchStart(e: TouchEvent){
        e.stopPropagation();
        if(!this.stopped){
            clearInterval(this.timer);
            this.LunBoEle.style.transition = 'none';
            let moveX = this.cssTransform.bind(this)(this.LunBoEle, 'translateX');
                this.now = Math.round(-moveX / this.sliderWidth);
            if(this.now === 0){
                this.now = this.props.len / 2;
            }else if(this.now === this.props.len - 1){
                this.now = this.props.len / 2 - 1;
            }
            this.cssTransform(this.LunBoEle, 'translateX', -this.now * this.sliderWidth);
            this.startPoint = e.changedTouches[0].pageX;
            this.startEle = this.cssTransform.bind(this)(this.LunBoEle, 'translateX');
        }
    };
//移动
    touchMove(e: TouchEvent){
        e.preventDefault();
        e.stopPropagation();
        if(!this.stopped){
            let endPoint = e.changedTouches[0].pageX;
            let disX = endPoint - this.startPoint;
            this.cssTransform.bind(this)(this.LunBoEle, 'translateX', disX + this.startEle);
        }
    }
//平移结束
    touchEnd(e: TouchEvent){
        e.stopPropagation();
        if(!this.stopped){
            let moveX = this.cssTransform.bind(this)(this.LunBoEle, 'translateX');
            //这边我是对移动做了判断
            if(Math.abs(moveX) > Math.abs(this.now * this.sliderWidth)){
                this.now = Math.ceil(-moveX / this.sliderWidth);
            }else{
                this.now = Math.floor(-moveX / this.sliderWidth);
            }
            this.tab.bind(this)();
            this.auto.bind(this)();
        }
    }

    componentWillUnmount(){
        //注意这边的清楚很重要，因为用户在使用时如果后台修改，用户刷新，会导致下面的dot出现问题
        clearInterval(this.timer);
        //卸载的同时需要将所有事件清除掉
        this.SliderEle.removeEventListener('touchstart', this.touchstart, false);
        this.SliderEle.removeEventListener('touchmove', this.touchmove, false);
        this.SliderEle.removeEventListener('touchend', this.touchend, false);
    }
    //防止如果只有一张轮播图时进行轮播
    componentDidUpdate(){
        if((this.props.len / 2) === 1){
            clearInterval(this.timer);
            this.stopped = true;
        }
        else{
            this.stopped = false;
        }
    }
    render() {
        let itemNodes = this.props.items.map((item, idx) => {
            return <SliderItem item={item} count={this.props.len} key={'item' + idx} />;
        });
        let dotNodes = [];
        let count = this.props.len / 2;
        for(let i = 0; i < count; i++){
            //为第一个dot点加上selected
            dotNodes[i] = (
                <span key={'dot' + i} className={'slider-dot' + (i === 0 ? ' slider-dot-selected' : '')}>
                </span>
            );
        }
        return (
            <div className="slider">
                <ul className="lunbo" style={{width: (this.props.len) * 100 + '%'}}>
                    {itemNodes}
                </ul>
                <div className="slider-dots-wrap">
                    {dotNodes}
                </div>
            </div>