javascript - 滚动到页面底部时更改背景位置

Question

嗨，当页面一直滚动到底部时，我需要我的背景位置上升 50px。有什么办法吗？

Answer 1

$(window).scroll(function() {
   //Checking if scrolled to the bottom
   if($(window).scrollTop() + $(window).height() == $(document).height()) {
       //Adding background position CSS property to the desired element
       $('.YOUR-ELEMENT-CLASS').css('background-position', '0 50px');
   }

   else {
       $('.YOUR-ELEMENT-CLASS').css('background-position', 'default_values');
   }
});