鼠标经过事件不起作用

源自：9-22 编程练习

鼠标经过事件不起作用

<!DOCTYPE html>
<html>
<head>
   <meta charset="UTF-8">
   <title>Document</title>
<script type="text/javascript">


    window.onload = function(){
        var trs = document.getElementsByTagName("tr");

         for (var i = 0; i < trs.length; i++) {
            background(trs[i]);
        }
    }

     function background(object){
             object.onmouseover = function(){
                object.style.backgroundColor = #f2f2f2;
             }
             object.onmouseout = function(){
                object.style.backgroundColor = #fff;
             }
         }
   var num = 2;
     function addone(){
         num++;
         var tr = document.createElement("tr");
         var td1 = document.createElement("td");
         var td2 = document.createElement("td");
         var td3 = document.createElement("td");
         var table = document.getElementById("table");
         table.lastChild.appendChild(tr);
         tr.appendChild(td1);
         tr.appendChild(td2);
         tr.appendChild(td3);
         td1.innerHTML = "xh00" + num;
         td2.innerHTML = "第" + num +"位同学";
         td3.innerHTML = "<a href = 'javascript:;' onclick='del(this)'>删除</a>"
     }


     // 创建删除函数
     function del(object){
        var tr = object.parentNode.parentNode;
        tr.parentNode.removeChild(tr);
     }

</script>
</head>
<body>
   <table border="1" width="50%" id="table">
       <tr>
       <th>学号</th>
       <th>姓名</th>
       <th>操作</th>
       </tr>

       <tr>
       <td>xh001</td>
       <td>王小明</td>
       <td><a href="javascript:;" onclick="del(this)">删除</a></td>   
       </tr>

       <tr>
       <td>xh002</td>
       <td>刘小芳</td>
       <td><a href="javascript:;" onclick="del(this)" >删除</a></td>   
       </tr>

       </table>
       <input type="button" value="添加一行" onclick = "addone()" />   <!--在添加按钮上添加点击事件 -
</body>
</html>

提问者：不知所语 2016-04-12 13:27

鼠标经过事件不起作用

个回答