<!DOCTYPE?html>
<html>
<head>
??<meta?charset="UTF-8">
??<title>handler</title>
????<script?type="text/javascript">
????????function?showWord(){
??????????alert("hello?world!")
????????}
????????var?mybtn=document.getElementsByClassName('btn')[0];
????????var?eventUtil={
??????????addHandler:function(element,type,handler){
????????????if?(element.addEventListener)?{
??????????????element.addEventListener(type,handler,false);
????????????}?else?if?(element.attachEvent)?{
??????????????element.attachEvent('on'+type,handler);
????????????}?else{
??????????????element['on'+type]=handler;
????????????}
??????????}
????????}
????????eventUtil.addHandler(mybtn,'click',showWord())
??</script>
</head>
<body>
??<input?type="button"?value="try"??/>
</body>
</html>
2016-04-08
改為 ?eventUtil.addHandler(mybtn,'click',showWord) 就OK了！
如果直接寫showWord()就是直接調用，而showWord是在事件觸發一后系統幫你調用的。所以應該寫showWord
2016-03-30
因為你的警告框寫在最上面，瀏覽器還沒獲取到你的html代碼，就開始解析你的js部分了