$(window).scroll(function() {    // When scroll at bottom, invoked getData() function.    if ($(window).scrollTop() + $(window).height() == $(document).height()) {        if (trackLoad.groupNumber <= totalGroups && !trackLoad.loading) {            trackLoad.loading = true;      // Blocks other loading data again.            $('.animation_image').show();            $.getData(trackLoad);        }    }});

每当用户把滚动条拖到最底端时，就调用getData()方法获取数据，那么，我们需要把getData()方法和滚动条事件进行绑定，具体实现如上：