js实现遮罩层划出效果是生成div而不是显示

var getOneDiv=function(){ var div=document.createElement("div"); div.style.position="absolute"; div.style.display="block"; div.style.zIndex="10"; div.style.background="yellow"; div.addEventListener("mouseout",function(event){//我把它加在了这里，而这里监听的判断与之前的划入几乎如出一辙 var x=event.clientX; var y=event.clientY; left=x-test.offsetLeft; top=y-test.offsetTop; right=test.offsetLeft+test.offsetWidth-x; bottom=test.offsetTop+test.offsetHeight-y; arr=[]; arr.push(top); arr.push(right); arr.push(bottom); arr.push(left); var least=findLeast(arr); if(least==1){ } if(least==2){//还是距离和宽度的同时改变啊 div.style.left=test.offsetLeft+"px"; div.style.top=test.offsetTop+"px"; div.style.height=test.offsetHeight+"px"; div.style.width=width+"px"; var changeWidth2=setInterval(function(){ if(div.offsetLeft>=test.offsetLeft+test.offsetWidth){ clearInterval(changeWidth2); check=true;//关键点 }else{ marginLeft=marginLeft+10; width=width-10; div.style.width=width+"px"; div.style.left=marginLeft+"px"; } },30); } if(least==3){ } if(least==4){//向左划出，width作为全局变量，这次就是不断减小了 div.style.left=test.offsetLeft+"px"; div.style.top=test.offsetTop+"px"; div.style.height=test.offsetHeight+"px"; div.style.width=width+"px"; var changeWidth1=setInterval(function(){ if(div.offsetWidth<=0){ clearInterval(changeWidth1); check=true;//这里也比较关键哦 }else{ width=width-10; div.style.width=width+"px"; } },30); } }) return div; }