如何使用带有json动态成员的WCF DataContract [英] How to have a WCF DataContract with a json dynamic member

问题描述

在我正在从事的项目中，我们要求有一个DataContract，其中可以包含一些未定义的JSON.

at the project I am working on, we have a requirement to have a DataContract that can contain some undefined JSON.

DataMember是仅对客户端有意义的一些JSON.我们希望允许客户端向我们发送我们不知道的json.

The DataMember is some JSON that makes sense to the client only. We want to allow the client to send us json we do not know about.

示例:

public class Contract
{
    [DataMember]
    public int clientId;
    [DataMember]
    public string json;
}

很明显，具有这样的约定将要求客户端像这样对json进行转义:

Obviously, having a contract defined like that would require the client to escape the json like this:

{
    "clientId":1,
    "json": "{\"test\":\"json\"}"
}

显然，这不是我们所需要的.客户端应发送给我们的json应该如下所示:

Obviously, this is not what we need. The json the client should sent us should look like this:

{
    "clientId":1,
    "json": {"test":"json"}
}

我们调查了可能的解决方案:

Possible solutions we investigated:

1. 使用Stream作为请求正文的合同参数.可以，但是可以代替我们使用框架.
2. 将"json"定义为DynamicObject.不起作用.无法正确编写属性.
3. 使用Newtonsoft库，在WCF端点中更改默认协定序列化程序，以将所有输入序列化到JObject.我们还会根据请求处理序列化，这会在我们的应用程序中引起问题.我们宁愿避免这种方式.

有人可以解决这个问题吗?

Does anyone have a possible solution to this problem?

编辑

该服务提供其余的json资源.它使用webHttpBinding定义单个端点. 该操作的定义如下(为简单起见，将其简化):

The service offers rest json resources. It defines a single endpoint with webHttpBinding. The operation is defined like this (stripped down for simplicity):

[WebInvoke(Method = "POST", UriTemplate = "...", ResponseFormat = WebMessageFormat.Json, RequestFormat = WebMessageFormat.Json, BodyStyle = WebMessageBodyStyle.Bare)]
[OperationContract]
Stream Create(Contract c);

此外，该服务还具有以下属性:

Also, the service is decorated with following attribute:

[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Required)]

谢谢. JF

推荐答案

WCF(自4.5版开始)不支持将任意JSON反序列化为数据协定的一部分.您需要使用另一个实现此目的的序列化程序-JSON.NET是我个人喜欢的序列化程序.为了能够更改序列化程序，可以使用其他消息格式化程序，并在

WCF (as of 4.5) doesn't support deserializing arbitrary JSON as part of a data contract. You'll need to use another serializer which does that - JSON.NET is one which I personally like. To be able to change the serializer, you can use a different message formatter, and in the post at http://blogs.msdn.com/b/carlosfigueira/archive/2011/05/03/wcf-extensibility-message-formatters.aspx I have a sample which does exactly that - replaces the default serialization used by WCF with JSON.NET.

请注意，要使用该库接收任意JSON，您需要将"json"属性的类型更改为与JSON.NET，JToken中的任意JSON等效:

Notice that to receive arbitrary JSON using that library, you'll need to change the type of the "json" property to the equivalent of arbitrary JSON in JSON.NET, JToken:

public class Contract 
{ 
    [DataMember] 
    public int clientId; 
    [DataMember] 
    public Newtonsoft.Json.Linq.JToken json; 
} 

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