NewtonSoft.Json序列化和反序列化类IEnumerable类型&LT的财产; ISomeInterface> [英] NewtonSoft.Json Serialize and Deserialize class with property of type IEnumerable<ISomeInterface>

问题描述

我试图将一些代码来使用ASP.NET MVC的Web API生成JSON数据，而不是SOAP XML。

I am trying to move some code to consume ASP.NET MVC Web API generated Json data instead of SOAP Xml.

我遇到了一个问题，序列化和反序列化类型的属性：

I have run into a problem with serializing and deserializing properties of type:

IEnumerable<ISomeInterface>.

下面是一个简单的例子：

Here is a simple example:

public interface ISample{
  int SampleId { get; set; }
}
public class Sample : ISample{
  public int SampleId { get; set; }
}
public class SampleGroup{
  public int GroupId { get; set; }
  public IEnumerable<ISample> Samples { get; set; }
 }
}

我可以很容易地与序列化SampleGroup的实例：

I can serialize instances of SampleGroup easily with:

var sz = JsonConvert.SerializeObject( sampleGroupInstance );

不过相应的反序列化失败：

However the corresponding deserialize fails:

JsonConvert.DeserializeObject<SampleGroup>( sz );

与此异常消息：

无法创建类型JsonSerializationExample.ISample的一个实例。类型是一个接口或抽象类，不能instantated。

"Could not create an instance of type JsonSerializationExample.ISample. Type is an interface or abstract class and cannot be instantated."

如果我得到一个JsonConverter我可以装点我的财产如下：

If I derive a JsonConverter I can decorate my property as follows:

[JsonConverter( typeof (SamplesJsonConverter) )]
public IEnumerable<ISample> Samples { get; set; }

下面是JsonConverter：

Here is the JsonConverter:

public class SamplesJsonConverter : JsonConverter{
  public override bool CanConvert( Type objectType ){
    return ( objectType == typeof (IEnumerable<ISample>) );
  }

  public override object ReadJson( JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer ){
    var jA = JArray.Load( reader );
    return jA.Select( jl => serializer.Deserialize<Sample>( new JTokenReader( jl ) ) ).Cast<ISample>( ).ToList( );
  }

  public override void WriteJson( JsonWriter writer, object value, JsonSerializer serializer ){
    ... What works here?
  }
}

这转换器解决了反序列化的问题，但我想不出如何编写该WriteJson方法来获取序列再次合作。

This converter solves the deserialization problem but I cannot figure how to code the WriteJson method to get serialization working again.

任何人可以帮助？

这是一个正确的方式来解决摆在首位的问题？

Is this a "correct" way to solve the problem in the first place?

推荐答案

您不需要使用 JsonConverterAttribute ，保持模型的清洁，还可以使用 CustomCreationConverter ，该代码是简单的：

You don't need to use JsonConverterAttribute, keep your model clean, also use CustomCreationConverter, the code is simpler:

public class SampleConverter : CustomCreationConverter<ISample>
{
    public override ISample Create(Type objectType)
    {
        return new Sample();
    }
}

然后：

Then:

var sz = JsonConvert.SerializeObject( sampleGroupInstance );
JsonConvert.DeserializeObject<SampleGroup>( sz, new SampleConverter());

文件：的 与反序列化CustomCreationConverter

这篇关于NewtonSoft.Json序列化和反序列化类IEnumerable类型&LT的财产; ISomeInterface>的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！