EXT扩展实例:在FieldSet上添加一个关闭按钮

开发环境 ExtJS 4.07

Ext.onReady(function () {
        Ext.define('Ext.form.ClosableFieldSet', {
            extend: 'Ext.form.FieldSet',
            alias: 'widget.closablefieldset',
　　　　　　　//覆盖父类的方法
            initLegend: function () {
                var me = this;
                me.callParent(arguments);
                if (!me.legend.closable) {
                    me.legend.insert(1, Ext.widget('tool', {
                        type: 'close',
                        handler: me.onCloseClick,
                        scope: me
                    }));
                    me.legend.closable = true;
                }
            },
            onCloseClick: function () {
                if (this.ownerCt) {
                    this.ownerCt.remove(this, true);
                }
            }
        });
        Ext.create('Ext.form.Panel', {
            title: 'Closable FieldSet',
            bodyPadding: 10,
             550,
            renderTo:Ext.getBody(),
          
            items: [
            {
                xtype: 'closablefieldset',
                columnWidth: 0.5,
                title: '测试',
                collapsible: true,
                defaultType: 'textfield',
                defaults: { anchor: '100%' },
                layout: 'anchor',
                items: [
                    {
                        fieldLabel: 'Field 1',
                        name: 'field1'
                    },
                    {
                        fieldLabel: 'Field 2',
                        name: 'field2'
                    }
                ]
            }
            ]
        });
    });