将EF模型序列化为Json时的循环引用 [英] Circular reference while serializing EF model to Json

问题描述

我知道这个问题在很多时候都是很多关于这个问题的问题，但是没有一个解决了我的问题。

我正在使用MVC 5与实体框架6和Newtonsoft.Json。

我有这种例外情况：

  Service =>员工=>服务
  

当我尝试序列化一个服务对象在我看来，像这样：

  var arr = @ Html.Raw（@ JsonConvert.SerializeObject（Model.Services）） ; 
  

在序列化类型的对象时，我获得了循环引用。

我在这里找到的所有答案都说这是很难解决的，我应该添加

  GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings 
 .PreserveReferencesHandling = PreserveReferencesHandling.All; 
 
 GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings 
 .ReferenceLoopHandling = ReferenceLoopHandling.Serialize; 
  

在我的 Global.asax 文件中。 / p>

嗯，我没有，只是不行。我在MSDN上看了一堆文章，他们都说同样的话。我不知道为什么，但它对我来说不起作用。

我可以让它工作的唯一方法是在我的...中创建整个序列化上下文控制器：

  var settings = new JsonSerializerSettings 
 {
 PreserveReferencesHandling = PreserveReferencesHandling.All，
 ReferenceLoopHandling = ReferenceLoopHandling.Serialize 
}; 
 
 
 var serializer = JsonSerializer.Create（settings）; 
 var msmStream = new MemoryStream（）; 
 var txtWriter = new StreamWriter（msmStream）; 
 var writer = new JsonTextWriter（txtWriter）{Formatting = Formatting.Indented}; 
 serializer.Serialize（writer，services）; 
 
 var json = Encoding.ASCII.GetString（msmStream.GetBuffer（））; 
  

但是，这是一个可怕的可怕解决方案，特别是如果我从我的视图模型序列化一个属性在飞行中的视野。它也击败了全局配置的整个目的。

有没有人面临这个问题？

解决方案

您需要将DefaultSettings更改为新的。

  JsonConvert.DefaultSettings =（）= >新的JsonSerializerSettings 
 {
 PreserveReferencesHandling = PreserveReferencesHandling.All，
 ReferenceLoopHandling = ReferenceLoopHandling.Serialize 
}; 
  

来源

I know that are tons of questions related to this topic all over SO but none of them solved my problem.

I'm using MVC 5 with Entity Framework 6 and Newtonsoft.Json.

I have the usual scenario for this exception:

Service => Staff => Service

When I try to serialize a service object in my view, like this:

var arr = @Html.Raw(@JsonConvert.SerializeObject(Model.Services));

I get the "circular reference was detected while serializing an object of type..." exception.

All the answers I found here say it is wasy to solve, I should just add

GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings
            .PreserveReferencesHandling = PreserveReferencesHandling.All;

GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings
        .ReferenceLoopHandling = ReferenceLoopHandling.Serialize;

in my Global.asax file.

Well, I did, and it just doesn't work. I read a bunch of articles on MSDN an they all say the same thing. I don't know why, but it just doesn't work for me.

The only way I could make it work, was to create the whole serialization context in my controller:

var settings = new JsonSerializerSettings
{
    PreserveReferencesHandling = PreserveReferencesHandling.All,
    ReferenceLoopHandling = ReferenceLoopHandling.Serialize
};


var serializer = JsonSerializer.Create(settings);
var msmStream = new MemoryStream();
var txtWriter = new StreamWriter(msmStream);
var writer = new JsonTextWriter(txtWriter) { Formatting = Formatting.Indented };
serializer.Serialize(writer, services);

var json = Encoding.ASCII.GetString(msmStream.GetBuffer());

However, this is a terrible terrible solution, specially if I'm serializing a property from my view model on the fly in the view. It also defeats the whole purpose of a "global configuration".

Has anybody faced this problem?

解决方案

You need to change the DefaultSettings to new ones.

JsonConvert.DefaultSettings = () => new JsonSerializerSettings
{
    PreserveReferencesHandling = PreserveReferencesHandling.All,
    ReferenceLoopHandling = ReferenceLoopHandling.Serialize
};

Source

这篇关于将EF模型序列化为Json时的循环引用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！