XAF 中如何存储筛选条件

using System;
using System.Collections.Generic;
using System.Text;
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.SystemModule;
using DevExpress.ExpressApp.Actions;

namespace Solution1.Module {
    public class FilterControllerExtender : Controller {
        protected override void OnFrameAssigned() {
            base.OnFrameAssigned();
            Frame.GetController<FilterController>().FullTextFilterAction.Executed += new EventHandler<DevExpress.ExpressApp.Actions.ActionBaseEventArgs>(FullTextFilterAction_Executed);
            Frame.GetController<FilterController>().Activated += new EventHandler(FilterControllerExtender_Activated);
        }

        void FilterControllerExtender_Activated(object sender, EventArgs e) {
            string currentValue = Frame.GetController<FilterController>().FullTextFilterAction.Value as string;
            Frame.GetController<FilterController>().FullTextFilterAction.DoExecute(
                Frame.View.Info.GetAttributeValue("FilterByText_CurrentFilter", currentValue));
        }

        void FullTextFilterAction_Executed(object sender, DevExpress.ExpressApp.Actions.ActionBaseEventArgs e) {
            string currentValue = ((ParametrizedAction)e.Action).Value as string;
            if(Frame.View != null) {
                Frame.View.Info.SetAttribute("FilterByText_CurrentFilter", currentValue);
            }
        }
    }
}