如何在 WCF 中使用自定义序列化或反序列化来强制数据联系人的每个属性上有一个新实例？

Question

我与许多具有自定义类的成员有一个数据联系人，

如果反序列化时该属性为空，我想强制创建一个新实例。

有办法做到这一点吗？

Answer 1

如果您使用 DataContract 序列化，则可以使用 OnDeserialized 属性覆盖其默认行为。

来自MSDN：当应用于方法，指定在对象图中的对象反序列化期间调用该方法。相对于图中其他对象的反序列化顺序是不确定的。

这是我的示例代码：

namespace MySpace
{

  public class MyCustomClass
  {
    public string MyStrData { get; set; }
  }

  [DataContract]
  public class Data
  {
    [DataMember]
    public int mInt;

    [DataMember]
    public MyCustomClass MyCustonObj;



    [OnDeserialized]
    void OnDeserialized(StreamingContext c)
    {
      if (MyCustonObj == null)
      {
        MyCustonObj = new MyCustomClass();
        MyCustonObj.MyStrData = "Overridden in serialization";
      }
    }

    [OnDeserializing]
    void OnDeserializing(StreamingContext c)
    {
      if (MyCustonObj == null)
      {
        MyCustonObj = new MyCustomClass();
        MyCustonObj.MyStrData = "Overridden in  deserializing";
      }
    }

    [OnSerialized]
    void OnSerialized(StreamingContext c)
    {
       // if you wan to  do somehing when serialized here or just remove them

    }

    [OnSerializing]
    void OnSerializing(StreamingContext c)
    {
       // if you wan to  do somehing during serializing here or just remove them    
    }
  }


}
[ServiceContract]
public interface IService
{
  [OperationContract]
  Data Method(Data dd);
}

public class Service : IService
{
  public Data Method(Data dd)
  {
    return dd;
  }
}

class Program
{
  static void Main(string[] args)
  {
    string Url = "http://localhost:8000/";
    Binding binding = new BasicHttpBinding();
    ServiceHost host = new ServiceHost(typeof(Service));
    host.AddServiceEndpoint(typeof(IService), binding, Url);
    host.Open();
    ChannelFactory<IService> fac = new ChannelFactory<IService>(binding);
    fac.Open();
    IService proxy = fac.CreateChannel(new EndpointAddress(Url));
    Data d = new Data();
    d.mInt = 5;
    Console.WriteLine("Data before calling service " + d.mInt);
    Console.WriteLine("Data before calling service " + (d.MyCustonObj == null ? "null" : d.MyCustonObj.MyStrData));
    d = proxy.Method(d);
    fac.Close();
    host.Close();
    Console.WriteLine("Data after calling service " + d.mInt);
    Console.WriteLine("Data after calling service " + d.MyCustonObj.MyStrData);
    Console.ReadLine();
  }
}