<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>test.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type="text/javascript">
document.getElementById('test').onclick=function(){alert('没事干点我干吗?')}
</script> </head> <body>
<span id="test" class="multi_delete">删除</span>
</body>
</html>这个代码的js竟然不能执行 我简直是无语 这哪里错了嘛 唉 不知道说什么好了 真**麻烦
window.onload=function(){ document.getElementById('test').onclick=function(){alert('没事干点我干吗?')} };
</script>为啥要把代码放在window.onload事件里呢,主要是因为必先有span元素,才能以用getElementById,否则你是得不到span元素的。
“document.getElementById("...")为空或不是对象。”之类的错误。
要么你把这句话写在HTML代码的最后,要么就按照1楼所说,使用window.onload去执行。
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>test.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
</head> <body>
<span id="test" class="multi_delete">删除</span>
</body>
<script type="text/javascript">
document.getElementById('test').onclick=function(){alert('没事干点我干吗?')}
</script>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>test.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
</head> <body>
<span id="test" class="multi_delete">删除</span>
</body>
</html>
<script type="text/javascript">
//换个位置,因为放前面的话span还没有加载就执行document.getElementById('test'),当然不行
document.getElementById('test').onclick=function(){alert('没事干点我干吗?')}
</script>
这里获取不了“test” 这个属性,将script 的代码放到
<span id="test" class="multi_delete">删除</span>
后面