解决ie 背景图fixed 滚动出现抖动

插入脚本

if(navigator.userAgent.match(/Trident\/7\./)) {
      document.body.addEventListener && document.body.addEventListener("mousewheel", function() {
        event.preventDefault();
        var wd = event.wheelDelta;
        var csp = window.pageYOffset;
        window.scrollTo(0, csp - wd);
      });
    }