我尝试序列化从实体数据模型.edmx自动生成的POCO类,当我使用

JsonConvert.SerializeObject 

我得到了以下错误:

为System.data.entity类型检测到自我引用循环错误。

我怎么解决这个问题?


当前回答

我喜欢从Application_Start()做它的解决方案,在这里的答案

显然,我不能在JavaScript中使用我的函数中的配置访问json对象,因为在DalSoft的答案中返回的对象在对象的(键,val)上都有“\n \r”。

不管怎样,只要能工作就好(因为不同的方法在不同的场景下工作,这取决于所提出的意见和问题),尽管最好采用一种标准的方法,并提供一些良好的文档支持该方法。

其他回答

对于. net Core 3.0,更新Startup.cs类,如下所示。

public void ConfigureServices(IServiceCollection services)
{
...

services.AddControllers()
    .AddNewtonsoftJson(
        options => options.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore
    );

...
}

参见:https://devblogs.microsoft.com/aspnet/asp-net-core-updates-in-net-core-3-0-preview-5/

最好的解决方案是从Web API中的循环引用处理(这个答案的大部分都是从这里复制的):

修复1:全局忽略循环引用

(我已经选择/尝试了这一个,就像其他许多人一样)

The json.net serializer has an option to ignore circular references. Put the following code in WebApiConfig.cs file: config.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore; The simple fix will make serializer to ignore the reference which will cause a loop. However, it has limitations: The data loses the looping reference information The fix only applies to JSON.net The level of references can't be controlled if there is a deep reference chain

如果你想在非api的ASP中使用这个修复。NET项目,你可以添加上述行到Global.asax.cs,但首先添加:

var config = GlobalConfiguration.Configuration;

如果你想在.Net Core项目中使用它,你可以将Startup.cs更改为:

var mvc = services.AddMvc(options =>
{
   ...
})
.AddJsonOptions(x => x.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore);

Fix 2: Preserving circular reference globally This second fix is similar to the first. Just change the code to: config.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Serialize; config.Formatters.JsonFormatter.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects; The data shape will be changed after applying this setting. [ { "$id":"1", "Category":{ "$id":"2", "Products":[ { "$id":"3", "Category":{ "$ref":"2" }, "Id":2, "Name":"Yogurt" }, { "$ref":"1" } ], "Id":1, "Name":"Diary" }, "Id":1, "Name":"Whole Milk" }, { "$ref":"3" } ] The $id and $ref keeps the all the references and makes the object graph level flat, but the client code needs to know the shape change to consume the data and it only applies to JSON.NET serializer as well. Fix 3: Ignore and preserve reference attributes This fix is decorate attributes on model class to control the serialization behavior on model or property level. To ignore the property: public class Category { public int Id { get; set; } public string Name { get; set; } [JsonIgnore] [IgnoreDataMember] public virtual ICollection<Product> Products { get; set; } } JsonIgnore is for JSON.NET and IgnoreDataMember is for XmlDCSerializer. To preserve reference: // Fix 3 [JsonObject(IsReference = true)] public class Category { public int Id { get; set; } public string Name { get; set; } // Fix 3 //[JsonIgnore] //[IgnoreDataMember] public virtual ICollection<Product> Products { get; set; } } [DataContract(IsReference = true)] public class Product { [Key] public int Id { get; set; } [DataMember] public string Name { get; set; } [DataMember] public virtual Category Category { get; set; } } JsonObject(IsReference = true)] is for JSON.NET and [DataContract(IsReference = true)] is for XmlDCSerializer. Note that: after applying DataContract on class, you need to add DataMember to properties that you want to serialize. The attributes can be applied on both json and xml serializer and gives more controls on model class.

没有循环这为我工作- ReferenceLoopHandling =引用eloophandling。忽略,

我已经在这里解决了所有问题——实体框架子序列化与。net Core 2 WebAPI https://gist.github.com/Kaidanov/f9ad0d79238494432f32b8407942c606

感谢任何评论。 也许有人可以用一下。

人们已经讨论过将[JsonIgnore]添加到类中的虚拟属性,例如:

[JsonIgnore]
public virtual Project Project { get; set; }

我还将分享另一个选项,[JsonProperty(NullValueHandling = NullValueHandling. ignore)],仅当它为空时才从序列化中省略该属性:

[JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
public virtual Project Project { get; set; }

我的问题解决了自定义配置JsonSerializerSettings:

services.AddMvc(
  // ...
               ).AddJsonOptions(opt =>
                 {
                opt.SerializerSettings.ReferenceLoopHandling =
                    Newtonsoft.Json.ReferenceLoopHandling.Serialize;
                opt.SerializerSettings.PreserveReferencesHandling =
                    Newtonsoft.Json.PreserveReferencesHandling.Objects;
                 });