xaf.domain object new 在属性上的用法

有如下业务对象定义:

using System;
using System.Linq;
using System.Text;
using DevExpress.Xpo;
using DevExpress.ExpressApp;
using System.ComponentModel;
using DevExpress.ExpressApp.DC;
using DevExpress.Data.Filtering;
using DevExpress.Persistent.Base;
using System.Collections.Generic;
using DevExpress.ExpressApp.Model;
using DevExpress.Persistent.BaseImpl;
using DevExpress.Persistent.Validation;

namespace TestXPO.Module.BusinessObjects
{
　　//往来单位:供应商,客户都是此类的派生类
[XafDefaultProperty("Name")]
[DefaultClassOptions]
public abstract class CompanyUnit : BaseObject
{
public CompanyUnit(Session s) : base(s)
{

}
public string Name
{
get { return GetPropertyValue<string>(nameof(Name)); }
set { SetPropertyValue(nameof(Name), value); }
}
}

[DefaultClassOptions]
[XafDefaultProperty(nameof(Address))]
public class Customer : CompanyUnit
{
public Customer(Session s) : base(s)
{

}
public string Address
{
get { return GetPropertyValue<string>(nameof(Address)); }
set { SetPropertyValue(nameof(Address), value); }
}
}

[DefaultClassOptions]
public class Provider : CompanyUnit
{
public Provider(Session s) : base(s)
{

}

}

public class Dept : CompanyUnit
{
public Dept(Session s) : base(s)
{

}
}

　　//存在某种单据基类:
　　//使用了CompanyUnit做为属性的类型
　　//在派生类中new TargetUnit重新定义此属性的类型,则可以成功
　　//可以达到使用真实类型过滤的作用.
　　//但如果使用Guid类型声明,并且派生类中用复杂类型,则不能成功
[DefaultClassOptions]
public class FormBase : BaseObject
{
public FormBase(Session session)
: base(session)
{
}

public CompanyUnit TargetUnit
{
get { return GetPropertyValue<CompanyUnit>(nameof(TargetUnit)); }
set { SetPropertyValue(nameof(TargetUnit), value); }
}
}

[DefaultClassOptions]
public class PMSOrder : FormBase
{
public PMSOrder(Session s) : base(s)
{

}
public new Provider TargetUnit
{
get { return GetPropertyValue<Provider>(nameof(TargetUnit)); }
set { SetPropertyValue(nameof(TargetUnit), value); }
}
}

[DefaultClassOptions]
public class SMSOrder : FormBase
{
public SMSOrder(Session s) : base(s)
{

}
public new Customer TargetUnit
{
get { return GetPropertyValue<Customer>(nameof(TargetUnit)); }
set { SetPropertyValue(nameof(TargetUnit), value); }
}
}
}

转载于:https://www.cnblogs.com/foreachlife/p/xaf_new_property.html