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ASP.NET MVCWebAPIコントローラーが返されますpublic IEnumerable<IMessage> Get()

IMessageに渡された既知の型コレクションから派生した型を登録する必要があるという例外がスローされますDataContractSerializer。

MVC Web APIプロジェクトでDataContractSerializer使用するための「既知のタイプ」を登録するにはどうすればよいですか？DataContractJSONSerializer

KnowType属性をインターフェースに配置することはできません。

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You need to put the KnownTypeAttribute on your IMessage implementations:

public interface  IMessage
{
    string Content { get; }
}

[KnownType(typeof(Message))]
public class Message : IMessage {
    public string Content{ get; set; }
}

[KnownType(typeof(Message2))]
public class Message2 : IMessage
{
    public string Content { get; set; }
}

So when calling the following action:

 public IEnumerable<IMessage> Get()
 {
     return new IMessage[] { new Message { Content = "value1" }, 
                             new Message2 { Content = "value2" } };
 }

The result will be this:

<ArrayOfanyType xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
    <anyType xmlns:d2p1="http://schemas.datacontract.org/2004/07/MvcApplication3.Controllers" i:type="d2p1:Message">
        <d2p1:Content>value1</d2p1:Content>
    </anyType>
    <anyType xmlns:d2p1="http://schemas.datacontract.org/2004/07/MvcApplication3.Controllers" i:type="d2p1:Message2">
       <d2p1:Content>value2</d2p1:Content>
    </anyType>
</ArrayOfanyType>

But this will only work one "way". So you cannot post back the same XML.

In order to the following action should work: 

public string Post(IEnumerable<IMessage> messages)

You need to register the known types globally, with configuring a DataContractSerializer and setting up in the GlobalConfiguration.Configuration.Formatters

GlobalConfiguration.Configuration
                   .Formatters
                   .XmlFormatter.SetSerializer<IEnumerable<IMessage>>(
                       new DataContractSerializer(typeof(IEnumerable<IMessage>), 
                           new[] { typeof(Message), typeof(Message2) }));

With using the configuration you don't need the KnownTypeAttribute on your implementation types.

于 2013-01-25T13:06:51.490 に答える