DDD-Mapper

应用层:Application
领域层:Domain Model Layer

为什么要用Mapper，随着技术的变化应用层的DTO会发生变化。大的业务契约不能够保证代码上线一次就成功。需要更换契约,SOA1->SOA2。契约中的长名称变成了短名称。由UserInvoiceItem 变成了  InvoiceTitle  如下

SOA 1.0版本

    [Serializable]
    public class UserInvoiceItem
    {
        public UserInvoiceItem();

        // Summary:
        //     发票ID
        public long InfoID { get; set; }
        //
        // Summary:
        //     发票标题
        public string Title { get; set; }
        //
        // Summary:
        //     Uid
        public string Uid { get; set; }
    }
}

SOA 2.0 版本

    // Summary:
    //     常用发票抬头信息
    [Serializable]
    [DebuggerStepThrough]
    [DesignerCategory("code")]
    [GeneratedCode("System.Xml", "4.0.30319.1009")]
    [ProtoContract]
    [XmlRoot(Namespace = "/platform/sps/InvoiceService/v1", IsNullable = false)]
    [XmlType(Namespace = "/platform/sps/InvoiceService/v1")]
    public class InvoiceTitle
    {
        public InvoiceTitle();

        // Summary:
        //     常用发票抬头ID
        [ProtoMember(2)]
        public long inId { get; set; }
        //
        // Summary:
        //     常用发票抬头
        [ProtoMember(3)]
        public string tle { get; set; }
        //
        // Summary:
        //     用户ID
        [ProtoMember(1)]
        public string uid { get; set; }
    }

UserInvoice.Items.Add(Mapper.Map<UserInvoice,UserInvoiceItem>(InvoiceItem));

UserInvoice.Items.Add(Mapper.Map<UserInvoice,InvoiceTitle>(InvoiceItem));