XAF 如何扩展应用程序模型(How to: Extend the Application Model )<一> ListView显示页脚信息

how to display a group footer for List Views

官方资料：http://documentation.devexpress.com/#Xaf/CustomDocument2785

using System;
using System.ComponentModel;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;

using DevExpress.ExpressApp;
using DevExpress.ExpressApp.Actions;
using DevExpress.Persistent.Base;
using DevExpress.ExpressApp.Model;
using DevExpress.Data;
using DevExpress.ExpressApp.Win.Editors;
using DevExpress.XtraGrid.Views.Grid;
using DevExpress.XtraGrid.Columns;

namespace XafExtendTest.Module.SystemModule
{
    public interface IModelListVewGroupFooterVisible : IModelNode
    {
        bool IsGroupFooterVisible { get; set; }
    }

    public interface IModelColumnExtenderForGroupFooter 
    {
        [DefaultValue(SummaryItemType.None)]
        SummaryItemType GroupFooterSummaryType { get; set; }
    }

    public  class GroupFooterVisibleListViewController : ViewController<ListView>,IModelExtender
    {
        private void View_InfoSynchronized(object sender, EventArgs e)
        {
            IModelListVewGroupFooterVisible modelListView = View.Model as IModelListVewGroupFooterVisible;
            if (modelListView != null && modelListView.IsGroupFooterVisible)
            {
                GridListEditor gridListEditor = View.Editor as GridListEditor;
                if (gridListEditor != null)
                {
                    GridView gridView = gridListEditor.GridView;
                    for (int i = 0; i < gridView.GroupSummary.Count; i++)
                    {
                        IModelColumnExtenderForGroupFooter modelColumn = View.Model.Columns[
                            gridView.GroupSummary[i].FieldName] as IModelColumnExtenderForGroupFooter;
                        if (modelColumn != null)
                        {
                            modelColumn.GroupFooterSummaryType = gridView.GroupSummary[i].SummaryType;
                        }
                    }
                }
            }
        }
        protected override void OnViewControlsCreated()
        {
            base.OnViewControlsCreated();
            IModelListVewGroupFooterVisible modelListView = View.Model as IModelListVewGroupFooterVisible;
            if (modelListView != null && modelListView.IsGroupFooterVisible)
            {
                GridListEditor gridListEditor = View.Editor as GridListEditor;
                if (gridListEditor != null)
                {
                    GridView gridView = gridListEditor.GridView;
                    gridView.GroupFooterShowMode = GroupFooterShowMode.VisibleAlways;
                    foreach (IModelColumn modelColumn in View.Model.Columns)
                    {
                        IModelColumnExtenderForGroupFooter modelColumnExtender = modelColumn as IModelColumnExtenderForGroupFooter;
                        if (modelColumnExtender != null &&
                            modelColumnExtender.GroupFooterSummaryType != SummaryItemType.None)
                        {
                            GridColumn gridColumn = gridView.Columns[
                                modelColumn.ModelMember.MemberInfo.BindingName];
                            gridView.GroupSummary.Add(modelColumnExtender.GroupFooterSummaryType,
                                modelColumn.Id, gridColumn);
                        }
                    }
                }
            }
        }
        protected override void OnActivated()
        {
            base.OnActivated();
            View.InfoSynchronized += View_InfoSynchronized;
        }
        protected override void OnDeactivated()
        {
            View.InfoSynchronized -= View_InfoSynchronized;
            base.OnDeactivated();
        }

        void IModelExtender.ExtendModelInterfaces(ModelInterfaceExtenders extenders)
        {
            extenders.Add<IModelListView, IModelListVewGroupFooterVisible>();
            extenders.Add<IModelColumn, IModelColumnExtenderForGroupFooter>();
        }
    }


}