inheritance - 如何从WCF中未标记DataContractAttribute或SerializableAttribute的类继承？

Question

在WCF中，如何从未标记DataContractAttribute或SerializableAttribute的类继承并将其用作datacontract？

例如:我有一个自定义类，名为“EmailAttachment”，该类是从System.Net.Mail.Attachment继承的:

[DataContract]
public class EmailAttachment : Attachment
{
   [DataMember]
   public string AttachmentURL
   {
       set;
       get;
   }
   [DataMember]
   public string DisplayName
   {
       set;
       get;
   }
}

但是，当我发布服务时，它抛出了运行时错误，说明:

System.Runtime.Serialization.InvalidDataContractException: Type 'EmailAttachment' cannot inherit from a type that is not marked with DataContractAttribute or SerializableAttribute.

有什么解决方法？

Answer 1

这取决于您希望数据契约(Contract)的外观。您不能使用包装器而不是派生类吗？就像是:

[DataContract]
public class EmailAttachment
{
   public EmailAttachment(){}

   internal EmailAttachment(Attachment inner) {_attachment = inner;}

   [DataMember]
   public string AttachmentURL
   {
       set;
       get;
   }
   [DataMember]
   public string DisplayName
   {
       set;
       get;
   }

   private Attachment  _attachment;
}

如果要在数据协定中公开内部System.Mail.Attachment的任何状态，则可以添加DataMember属性以显示该状态。