有两种方法可以处理这个问题; 我最不喜欢的选项是使用DynamicType = true - 这更昂贵,但限制了可移植性和版本控制,并且对于预先不知道数据的情况没有要求。 我更喜欢的选项是为每个接口声明一个固定标识符,使其能够识别数据本身。以下是示例。
顺便说一下,DontAskWrapper是因为Serialize()使用GetType(),这意味着它无法检测到接口基础部分。 我猜我可以改进它,但这对于今天的v2有效。
using System.Diagnostics;
using System.IO;
using NUnit.Framework;
using ProtoBuf;
using ProtoBuf.Meta;
namespace Examples.Issues
{
[TestFixture]
public class SO7078615
{
[ProtoContract]
[ProtoInclude(1, typeof(DogBarkedEvent))]
public interface IMessage { }
public interface IEvent : IMessage { }
[ProtoContract]
public class DogBarkedEvent : IEvent
{
[ProtoMember(1)]
public string NameOfDog { get; set; }
[ProtoMember(2)]
public int Times { get; set; }
}
[ProtoContract]
class DontAskWrapper
{
[ProtoMember(1)]
public IMessage Message { get; set; }
}
[Test]
public void RoundTripAnUnknownMessage()
{
IMessage msg = new DogBarkedEvent
{
NameOfDog = "Woofy", Times = 5
}, copy;
var model = TypeModel.Create();
using(var ms = new MemoryStream())
{
var tmp = new DontAskWrapper {Message = msg};
model.Serialize(ms, tmp);
ms.Position = 0;
string hex = Program.GetByteString(ms.ToArray());
Debug.WriteLine(hex);
var wrapper = (DontAskWrapper)model.Deserialize(ms, null, typeof(DontAskWrapper));
copy = wrapper.Message;
}
Assert.IsInstanceOfType(typeof(DogBarkedEvent), copy);
var typed = (DogBarkedEvent)copy;
var orig = (DogBarkedEvent)msg;
Assert.AreEqual(orig.Times, typed.Times);
Assert.AreEqual(orig.NameOfDog, typed.NameOfDog);
}
}
}
以下是没有属性的相同内容:
public interface IMessage { }
public interface IEvent : IMessage { }
public class DogBarkedEvent : IEvent
{
public string NameOfDog { get; set; }
public int Times { get; set; }
}
class DontAskWrapper
{
public IMessage Message { get; set; }
}
[Test]
public void RoundTripAnUnknownMessage()
{
IMessage msg = new DogBarkedEvent
{
NameOfDog = "Woofy",
Times = 5
}, copy;
var model = TypeModel.Create();
model.Add(typeof (DogBarkedEvent), false).Add("NameOfDog", "Times");
model.Add(typeof (IMessage), false).AddSubType(1, typeof (DogBarkedEvent));
model.Add(typeof (DontAskWrapper), false).Add("Message");
using (var ms = new MemoryStream())
{
var tmp = new DontAskWrapper { Message = msg };
model.Serialize(ms, tmp);
ms.Position = 0;
string hex = Program.GetByteString(ms.ToArray());
Debug.WriteLine(hex);
var wrapper = (DontAskWrapper)model.Deserialize(ms, null, typeof(DontAskWrapper));
copy = wrapper.Message;
}
Assert.IsInstanceOfType(typeof(DogBarkedEvent), copy);
var typed = (DogBarkedEvent)copy;
var orig = (DogBarkedEvent)msg;
Assert.AreEqual(orig.Times, typed.Times);
Assert.AreEqual(orig.NameOfDog, typed.NameOfDog);
}
请注意,在这
两种情况下,
TypeModel
都应该被缓存和重复使用;它是线程安全的,因此可以被不同的线程并行地大量使用等。