combo 添加listeners，使用 initComponent、constructor 的区别

LocationCombo = Ext.extend(Ext.form.ComboBox,{

initComponent: function(){

var config = {

name: 'loactionCombo'

,hiddenName: 'loactionCombo'

,fieldLabel: '所在区域'

,store: [['-1','请选择...']]

,triggerAction: 'all'

,mode: 'local'

,autoScroll: true

,expandPanel : new LocationTree()

,listeners: {

'expand': function(){

alert('expand...');

// if(!combo.expanded){

// combo.expandPanel.render(combo.el);

// combo.doLayout();

// combo.expanded = true;

// //applyToMarkup

// }

}

,'collapse': function(){

alert('collapse');

//document.getElementById('tree').innerHTML='';

}

}

}

this.addListener('expand',function(){alert('2expand..')});

Ext.apply(this, config);

LocationCombo.superclass.initComponent.call(this);

}

});

使用initComponent时，在config对象中写listeners无效，需使用方法添加。而使用constructor则支持 在config对象中写listeners,但ext.2.0不支持constructor.