1 <!DOCTYPE html>
2 <html>
3 <head>
4 <meta charset="utf-8">
5 <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
6 <title>练习</title>
7 <style type="text/css">
8 div{width: 300px;height: 300px;border:1px solid #ccc;}
9 </style>
10 <script type="text/javascript">
11 window.onload=function (){
12 document.getElementById(‘btn‘).=function (){
13 document.getElementsByTagName(‘div‘)[0].style.background=‘red‘;
14 }
15 }
16 </script>
17 </head>
18 <body>
19 <input type="button" value="变红" id="btn"/>
20 <div></div>
21 </body>
22 </html>
因为button后面没有对要写的函数绑定事件
解决办法：
1 <!DOCTYPE html>
2 <html>
3 <head>
4 <meta charset="utf-8">
5 <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
6 <title>练习</title>
7 <style type="text/css">
8 div{width: 300px;height: 300px;border:1px solid #ccc;}
9 </style>
10 <script type="text/javascript">
11 window.onload=function (){
12 document.getElementById(‘btn‘).onclick=function (){
13 document.getElementsByTagName(‘div‘)[0].style.background=‘red‘;
14 }
15 }
16 </script>
17 </head>
18 <body>
19 <input type="button" value="变红" id="btn"/>
20 <div></div>
21 </body>
22 </html>
时间： 2024-10-09 17:46:33