DevExpress Xaf入门——关于树形结构对象的配置（DC模式）

  <connectionStrings>
    <add name="EasyTestConnectionString" connectionString="Integrated Security=SSPI;Pooling=false;Data Source=.\SQLEXPRESS;Initial Catalog=Solution2EasyTest" />
    <add name="ConnectionString" connectionString="Data Source=GUANBAOPC\SQLEXPRESS;Initial Catalog=Solution2DB;Persist Security Info=true;User ID=sa;Password=123" />
  </connectionStrings>

using System;
using System.Linq;
using System.Text;
using System.ComponentModel;
using DevExpress.ExpressApp;
using DevExpress.ExpressApp.DC;
using DevExpress.Data.Filtering;
using DevExpress.Persistent.Base;
using System.Collections.Generic;
using DevExpress.ExpressApp.Model;
using DevExpress.Persistent.Validation;
using DevExpress.Persistent.Base.General;
using DevExpress.ExpressApp.ConditionalAppearance;
using DevExpress.ExpressApp.Editors;

namespace Solution2.Module.BusinessObjects
{
    [DomainComponent]
    [DefaultClassOptions]
    [XafDisplayName("部门信息")]
    [Appearance("Single", Enabled = false, TargetItems="Name,Children,Parent", 
     Visibility = ViewItemVisibility.Hide, Criteria = "1=1")]
    public interface Department : ITreeNode
    {
        [XafDisplayName("部门名称")]
        string DepartmentName { get; set; }

        [XafDisplayName("部门编号")]
        string DepartmentCode { get; set; }

        [XafDisplayName("联系电话")]
        string ContactNumber { get; set; }

        [XafDisplayName("子部门")]
        IList<Department> ChildrenDepartment { get; }

        [XafDisplayName("父部门")]
        Department ParentDepartment { get; set; }
    }

    [DomainLogic(typeof(Department))]
    public class Department_Logic
    {
        public static string Get_Name(Department instance)
        {
            return instance.DepartmentName;
        }

        public static Department Get_Parent(Department instance)
        {
            return instance.ParentDepartment;
        }

        public static IBindingList Get_Children(Department instance)
        {
            return new BindingList<Department>(instance.ChildrenDepartment);
        }
    }
}