ext checkboxgroup 取值

 Ext.onReady(function(){
             var myCheckboxGroup = new  Ext.form.CheckboxGroup({
                 id:'myGroup' ,
                 xtype: 'checkboxgroup' ,
                 renderTo :'form-cb' ,
                 fieldLabel: 'Single Column' ,
                 itemCls: 'x-check-group-alt' ,
                 columns: 3 ,
                 items: [
                     {boxLabel: '唱歌' , name:  '1' },
                     {boxLabel: '游泳' , name:  '2' , checked:  true },
                     {boxLabel: '看书' , name:  '3' },
                     {boxLabel: '旅游' , name:  '4' },
                     {boxLabel: '游戏' , name:  '5' },
                     {boxLabel: '睡觉' , name:  '6' }
                 ]
             });

             //CheckboxGroup取值方法
             for  (var i =  0 ; i < myCheckboxGroup.items.length; i++)
             {
                 if  (myCheckboxGroup.items.itemAt(i).checked)
                 {
                     alert(myCheckboxGroup.items.itemAt(i).name);
                 }
             }
         });