window.onscroll=function(){ var osTop=document.documentElement.scrollTop || document.body.scrollTop;? if(osTop>=clientHeight){? obtn.style.display="block";? }else{? obtn.style.display="none";? }? if(!isTop){? clearInterval(timer);? } isTop=false;? }
求大神打救~按鈕顯示不出來,一直看不懂什么問題
kenyip
2017-02-11 11:34:15