extjs constructor 基本靠猜测
先代码：
????? father 中有 constructor 的情况，之后将这里的注释掉
????? constructor:function(name){
???????? alert('father1\'s'+name);?
????? }
?
???? 没有注释，结果会是：
??? father1's2012-3-9
?
??? 注释掉：结果是：
?? grandfather constructor2012-3-9
?
?
<script type="text/javascript"> Ext.define('grandfather',{ constructor:function(hello){ alert('grandfather constructor'+hello); }, testf:function(){ alert('grandfather test'); } }); Ext.define('father1',{ extend:'grandfather', constructor:function(name){ alert('father1\'s'+name); }, test:function(){ alert('test'); } }); Ext.define('son',{ extend:'father1', }); var inson; Ext.onReady(function () { inson=new son('2012-3-9'); }); </script>