滚动加载方法

/**

*

* @param {*} scrollClass

* @param {*} fn

* @param {*} preventLoad

* 滚动的元素id

* 滚动回调方法

* 锁死滚动的方法

*/

var initScroll = function(scrollClass,fn){
   var self = this; 
 
    var beforeScrollTop = document.body.scrollTop || document.documentElement.scrollTop;

    document.getElementById(scrollClass).addEventListener('scroll', function(e){
 
    var afterScrollTop = this.scrollTop || this.scrollTop,
    windowHeight = window.innerHeight,
    scrollHeight = this.scrollHeight,
    delta = afterScrollTop - beforeScrollTop;

    if( (afterScrollTop + windowHeight)/scrollHeight>=0.95 ){
        (typeof fn=='function') && fn();
    }

    //将新的滑动距离赋值给上一次的滑动
    beforeScrollTop = afterScrollTop;
})
}