Newtonsoft JSON序列化器返回空对象 [英] Newtonsoft json serializer returns empty object

问题描述

好吧-我已经将这个问题打了几个小时.是时候寻求帮助了.

Ok - I've been beating my head against this for a few of hours now. Time to ask for help.

我刚刚将我的Web应用程序项目升级到ASP.NET MVC 4 RC和新的WebApi. 我的网络api方法现在返回EMPTY json"{}"-即使我的对象已完全填充.

I have just upgraded my Web application project to ASP.NET MVC 4 RC, and the new WebApi. My web api method is now returning EMPTY json "{}" - even though my object is fully populated.

我已经用自己的MediaTypeFormatter替换了序列化程序，该介质类型也称为Newtonsoft Json序列化程序，这样我就可以挂接并看到工作正常. 我看到的是一个对象进入序列化器，并以"{}"的形式出现.

I have replace the serializer with my own MediaTypeFormatter that also calls the Newtonsoft Json serializer, just so I can hook in and see things working. What I see is an object going in to the serializer, and coming out as "{}".

此功能在我升级之前就可以使用.

This USED to work before I upgraded.

这是我的对象

[Serializable]
public class Parameters
{
    public string ApplicantName { get; set; }
}

我只是打电话给

var result = JsonConvert.SerializeObject(new Parameters(){ Name = "test" });

我回来了

"{}"

怎么回事?

其他人也有相同的问题...在浏览完Newtonsoft源代码后，我发现我们在最近的更改中也遇到了完全相同的问题.

Someone else having the same problem... after running through the Newtonsoft source code, I can see we're having the exact same problem from a recent change.

http://json.codeplex.com/discussions/357850

推荐答案

好-进行了许多更改，结果是对Json输出进行了相当大的更改.这些更改还包括如何应用自定义TypeConverters.

Ok - there have been numerous changes, which result is some pretty radical changes to the Json output. These changes also include how custom TypeConverters are applied.

我已经写了一个基本的解析器，(至少对我们而言)使Newtonsoft序列化器的行为更像基本的Serializable对象序列化器-即序列化所有PROPERTIES，并且不使用自定义TypeConverters ...

I have written a basic resolver which (for us at least) causes the Newtonsoft serializer to behave more like a basic Serializable object serializer - i.e. serializes all PROPERTIES, and doesnt use custom TypeConverters...

/// <summary>
/// A resolver that will serialize all properties, and ignore custom TypeConverter attributes.
/// </summary>
public class SerializableContractResolver : Newtonsoft.Json.Serialization.DefaultContractResolver
{
    protected override IList<Newtonsoft.Json.Serialization.JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
    {
        var properties = base.CreateProperties(type, memberSerialization);

        foreach (var p in properties)
            p.Ignored = false;

        return properties;
    }

    protected override Newtonsoft.Json.Serialization.JsonContract CreateContract(Type objectType)
    {
        var contract = base.CreateContract(objectType);

        if (contract is Newtonsoft.Json.Serialization.JsonStringContract)
            return CreateObjectContract(objectType);
        return contract;
    }
}

*注册* 在您的MvcApplication中，"Application_Start" ...

* REGISTRATION * In your MvcApplication "Application_Start"...

GlobalConfiguration.Configuration.Formatters
    .JsonFormatter.SerializerSettings.ContractResolver = 
        new SerializableContractResolver()
        {
            IgnoreSerializableAttribute = true
        };

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