c# - 使用代理的 XML 反序列化

Question

我有一个关于XML 类的反序列化的问题。我需要为 IList 使用代理，因为 XML 不会在接口上序列化/反序列化。我需要使用这个代理，因为 NHibernate 不接受列表，只接受接口。我的问题仅在反序列化时。序列化工作正常。

public class EmailCategory
    {
        [XmlAttribute("Id")]
        public virtual long Id { get; set; }
        [XmlAttribute("Name")]
        public virtual string Name { get; set; }
        protected internal virtual IList<EmailBranch> EmailBranches { get; set; }

        [XmlArray("EmailBranches")]
        [XmlArrayItem("EmailBranch", typeof(EmailBranch)]
        public List<EmailBranch> EmailBranchesProxy {
            get { return EmailBranches != null ? EmailBranches .ToList() : null; }
            set { EmailBranches = value; }
        }
    }

Answer 1

A DTO object is probably the cleanest. There's a whole range of issues that could crop up when you try to serialize database objects. However, if you still intend to serialize the object, here's a possible solution:

public class EmailCategory { [XmlAttribute("Id")] public virtual long Id { get; set; } [XmlAttribute("Name")] public virtual string Name { get; set; } protected internal virtual IList EmailBranches { get; set; } //private List _test = new List();

//[XmlArray("EmailBranches")]
//[XmlArrayItem("EmailBranch", typeof(EmailBranch))]
//public virtual List<EmailBranch> EmailBranchesProxy {
//    get { return EmailBranches != null ? EmailBranches.ToList() : null; }
//    set { EmailBranches = value; }
//}

[XmlArray("EmailBranches")]
[XmlArrayItem("EmailBranch", typeof(EmailBranch))]
public virtual List<EmailBranch> EmailBranchesProxy
{
    get 
    {
        var proxy = EmailBranches as List<EmailBranch>;
        if (proxy == null && EmailBranches != null)
        {
            proxy = EmailBranches.ToList();
        }

        return proxy;
    }
    set { EmailBranches = value; }
}

public EmailCategory()
{
    EmailBranches = new List<EmailBranch>();
}

}

The problem you're having is in this line: get { return EmailBranches != null ? EmailBranches .ToList() : null; }. The deserialization process uses the get method and then adds items to the collection. Since you're returning null or a new List object, this does not represent the original EmailBranches collection, hence the serializer correctly deserializes a new EmailBranch object, but addes it to the wrong collection.

The fix, as above, is to initialize the EmailBranches collection inside the constructor (hence it won't be null ... which is probably a good idea anyway) and then type checking in the proxy property appropriately.