添加或创建元素，最新消息在最上方 

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Examples</title>
<meta name="description" content="">
<meta name="keywords" content="">
<link href="" rel="stylesheet">
<script>
    window.onload=function(){
        var oUl=document.getElementById("ul");
        var oBtn=document.getElementById("btn1");
        var oTxt=document.getElementById("txt1");
        var oLi=oUl.getElementsByTagName('li');
        oBtn.onclick=function(){
            var oA=document.createElement('li');
                oA.innerHTML=oTxt.value;
                if(oLi.length>0){
                    oUl.insertBefore(oA,oLi[0]);
                }else{
                    oUl.appendChild(oA); 
                }  
            }
        }
      
        
    
</script>
</head>
<body>
    <h2>创建DOM元素</h2>
    <input type="text" id="txt1">
    <input type="button" value="创建" id="btn1">
    <ul id="ul"></ul>
</body>
</html>

 

posted @ 2017-12-16 21:26  IT文艺女  阅读(176)  评论(0)    收藏  举报