<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<script>
var obtn = document.getElementById('btn1');
function an ()
{
alert('a');
}
obtn.onclick=an;
</script>
<body>
<input id="btn1" type="button" value="按钮"/>
</body>
</html>这个提取行间事件为什么实现不了
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<script>
var obtn = document.getElementById('btn1');
function an ()
{
alert('a');
}
obtn.onclick=an;
</script>
<body>
<input id="btn1" type="button" value="按钮"/>
</body>
</html>这个提取行间事件为什么实现不了
<input id="btn1" type="button" value="按钮"/>
<script>
var obtn = document.getElementById('btn1');
function an ()
{
alert('a');
}
obtn.onclick=an;
</script>
</body>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head><body>
<input id="btn1" type="button" value="按钮"/>
</body>
</html><script>
var obtn = document.getElementById('btn1');
function an()
{
alert('a');
}
obtn.onclick=an;
</script>
放到html最后面,页面加载完成了,使用就可以了