blocks|key|3068188|text|对我来说，这是一个循环引用的问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3068189|被接受的答案对我不起作用，因为它只改变了JSON格式化程序的行为，但是当我从浏览器调用服务时，我得到的是XML。|3068190|为了解决这个问题，我关闭了XML，只强制返回JSON。|3068191|在Global.asax文件中，将以下行放在Application_Start方法的顶部：|3068192|GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling+=+Newtonsoft.Json.ReferenceLoopHandling.Ignore;
GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);|code-block|syntax|javascript|3068193|现在只返回JSON结果。如果需要XML结果，则需要找到不同的解决方案。|3068194|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|S|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|T|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|U|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

For me this was a problem with circular referencing. 

The accepted answer did not work for me because it only changes the behaviour of the JSON formatter, but I was getting XML when I called the service from the browser.

To fix this, I switched off XML and forced only JSON to be returned. 

In the Global.asax file, put the following lines at the top of your Application_Start method: 

<pre><code>GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);
</code></pre>

Now only JSON results will be returned. If you need XML results, you will need to find a different solution.

blocks|key|209876|text|在global.asax文件的Application_start()方法中，添加以下行：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|209877|GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling+=+Newtonsoft.Json.ReferenceLoopHandling.Ignore;|code-block|syntax|javascript|209878|我希望这对你有帮助！|209879|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

in your global.asax file, in the Application_start() method add this line:

<pre><code>GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
</code></pre>

I hope that helps you!

blocks|key|3068079|text|我也有同样的问题。我解决了这个问题。我将默认构造函数放到了DTO类中。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3068080|例如：|3068081|public+class+User
{
++++public+User()
++++{
++++}
}|code-block|syntax|javascript|3068082|希望它能和你一起工作！|3068083|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|O|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I got the same problem. And I solved it. I put the default constructor to the DTO class.

Ex:

<pre><code>public class User
{
 public User()
 {
 }
}
</code></pre>

Hope it work with you!

blocks|key|2854459|text|将其放入构造器中。希望这能解决这个问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2854460|++++public+MyController()
++++{

++++++++db.Configuration.ProxyCreationEnabled+=+false;
++++}|code-block|syntax|javascript|2854461|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Put this in constructor. Hope this solve the problem:

<pre><code> public MyController()
 {

 db.Configuration.ProxyCreationEnabled = false;
 }
</code></pre>

blocks|key|2854487|text|我找到了两个解决方案。第一个也是最容易实现的方法是将任何IEnumerables、ICollections更改为List类型。WebAPI可以序列化此对象，但不能序列化接口类型。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2854488|public+class+Store
{

++[StringLength(5)]
++++public+string+Zip5+{+get;+set;+}

++++public+virtual+List<StoreReport>+StoreReports+{+get;+set;+}++//use+a+list+here
+}|code-block|syntax|javascript|2854489|另一种选择是不使用原生JSON序列化程序，并在WebApi配置的Register方法中运行此覆盖：|2854490|++++++++var+json+=+config.Formatters.JsonFormatter;
++++++++json.SerializerSettings.PreserveReferencesHandling+=+Newtonsoft.Json.PreserveReferencesHandling.Objects;
++++++++config.Formatters.Remove(config.Formatters.XmlFormatter);|2854491|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I found two solutions to this. The first and easiest to implement is to change any IEnumerables, ICollections to a type of List. The WebAPI can serialize this objects, it however cannot serialize interface types. 

<pre><code>public class Store
{

 [StringLength(5)]
 public string Zip5 { get; set; }

 public virtual List&lt;StoreReport&gt; StoreReports { get; set; } //use a list here
 }
</code></pre>

The other option is to not use the native JSON serializer and run this override in the Register method of the WebApi Config:

<pre><code> var json = config.Formatters.JsonFormatter;
 json.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects;
 config.Formatters.Remove(config.Formatters.XmlFormatter);
</code></pre>

blocks|key|2854548|text|解决方案很简单。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2854549|在LINQ查询之后添加.ToList()+(如果需要，也可以添加ToDictionary+)。|2854550|它将执行数据的急切加载而不是延迟加载|2854551|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|H|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|I|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|G|$]]

Solution is simple.

After LINQ query add .ToList() (or ToDictionary if need).

It will do eager loading than lazy loading of the data

blocks|key|3068207|text|**当从请求web+api/wcf/...调用时发生此错误...从客户端，但作为副作用，您将需要包括包含关键字依赖关系。**|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3068208|public+CustomerPortalContext()
++++++++++++:+base("Name=CustomerPortalContext")
++++++++{
++++++++++++base.Configuration.ProxyCreationEnabled+=+false;
++++++++}|code-block|syntax|javascript|3068209|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

**
this bug occur when calling from request web api/wcf/... from client side, but as side effect, you will need to include depending relations by include keyword.
**

<pre><code>public CustomerPortalContext()
 : base("Name=CustomerPortalContext")
 {
 base.Configuration.ProxyCreationEnabled = false;
 }
</code></pre>

blocks|key|209986|text|如果您正在使用EF，除了在Global.asax上添加以下代码|type|unstyled|depth|inlineStyleRanges|entityRanges|data|209987|++++++++++++GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling+=+Newtonsoft.Json.ReferenceLoopHandling.Ignore;
++++++++GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);++++++++++|code-block|syntax|javascript|209988|别忘了导入|209989|using+System.Data.Entity;|209990|然后你可以返回你自己的EF模型|209991|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

If you are working with EF, besides adding the code below on Global.asax

<pre><code> GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
 GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter); 
</code></pre>

Dont`t forget to import 

<pre><code>using System.Data.Entity;
</code></pre>

Then you can return your own EF Models

blocks|key|3068090|text|请查看web+api文档以了解此问题，Handling+Circular+Object+References|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3068091|问候|3068092|entityMap|0|LINK|mutability|MUTABLE|url|http://www.asp.net/web-api/overview/formats-and-model-binding/json-and-xml-serialization#handling_circular_object_references^0|J|Z|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@$A|O|B|P|1|Q]]|C|$]]|$1|D|3|E|5|6|7|R|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]]]

please check the web api documentation for this problem, <a href="http://www.asp.net/web-api/overview/formats-and-model-binding/json-and-xml-serialization#handling_circular_object_references" rel="nofollow">Handling Circular Object References</a>

Regards

blocks|key|214508|text|如果将web+api与实体框架一起使用，则解决方案可以是Failed+to+serialize+the+response+in+Web+API+with+Json|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|214509|基本上，您需要创建一个对应于每个EF模型的模型，这消除了类之间的依赖关系，并允许轻松序列化。|214510|代码：(取自引用的链接)|214511|创建UserModel|214512|public+class+UserModel
{
++++public+string+FirstName+{+get;+set;+}
++++public+string+LastName+{+get;+set;+}
}|code-block|syntax|javascript|214513|更改我的方法GetAll()|214514|public+IEnumerable<UserModel>+GetAll()
{
++++using+(Database+db+=+new+Database+())
++++{
++++++++List<UserModel>+listOfUsers+=+new+List<UserModel>();
++++++++UserModel+userModel+=+new+UserModel();
++++++++foreach(var+user+in+db.Users)
++++++++{
+++++++++++userModel.FirstName+=+user.FirstName;
+++++++++++userModel.LastName+=+user.LastName;
+++++++++++listOfUsers.Add(userModel);
++++++++}
++++++++IEnumerable<UserModel>+users+=+listOfUsers;

++++++++return+users;
++++}
}|214515|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/23098191/failed-to-serialize-the-response-in-web-api-with-json^0|S|1H|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@$A|11|B|12|1|13]]|C|$]]|$1|D|3|E|5|6|7|14|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|15|8|@]|9|@]|C|$]]|$1|H|3|I|5|6|7|16|8|@]|9|@]|C|$]]|$1|J|3|K|5|L|7|17|8|@]|9|@]|C|$M|N]]|$1|O|3|P|5|6|7|18|8|@]|9|@]|C|$]]|$1|Q|3|R|5|L|7|19|8|@]|9|@]|C|$M|N]]|$1|S|3|-4|5|6|7|1A|8|@]|9|@]|C|$]]]|T|$U|$5|V|W|X|C|$Y|Z]]]]

If you use web api with Entity Framework, a solution can be
<a href="https://stackoverflow.com/questions/23098191/failed-to-serialize-the-response-in-web-api-with-json">Failed to serialize the response in Web API with Json</a>

Basically, you need to create a model corresponding to each EF model, this removes dependencies between classes and allow easy serialization.

Code: (taken from the referenced link)

Create a UserModel

<pre><code>public class UserModel
{
 public string FirstName { get; set; }
 public string LastName { get; set; }
}
</code></pre>

Change my method GetAll()

<pre><code>public IEnumerable&lt;UserModel&gt; GetAll()
{
 using (Database db = new Database ())
 {
 List&lt;UserModel&gt; listOfUsers = new List&lt;UserModel&gt;();
 UserModel userModel = new UserModel();
 foreach(var user in db.Users)
 {
 userModel.FirstName = user.FirstName;
 userModel.LastName = user.LastName;
 listOfUsers.Add(userModel);
 }
 IEnumerable&lt;UserModel&gt; users = listOfUsers;

 return users;
 }
}
</code></pre>

blocks|key|3068360|text|Default+Entity+6+use+XML+to+apis，在您的项目中，找到文件"Global.asax“File，并添加以下行：|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|3068361|GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);|code-block|syntax|javascript|3068362|此行删除XML格式化程序。|3068363|entityMap^0|0|O|18|H|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

Default Entity 6 use XML to apis, in your project, find the file "Global.asax" File and add this line:

<pre><code>GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);
</code></pre>

This line remove the XML Formatter.

blocks|key|209881|text|嗯，下面的内容可能会有所帮助。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|209882|我得到了同样的异常，在我的例子中，我首先传递了为实体代码创建的实际poco实体。因为它包含与其他实体的关系，所以我只在它上面创建了viewmapper/dto实体来返回。|209883|它现在运行得很好。|209884|Poco实体：|209885|public+class+Tag
{
public+int+Id{get;set;}
public+string+Title{get;set;}
public+IList<Location>+Locations{get;set;}
}|code-block|syntax|javascript|209886|ViewMapper/Dto|209887|public+class+TagResultsViewMapper
{
public+int+Id{get;set;}
public+string+Title{get;set;}
//just+remove+the+following+relationship+
//public+IList<Location>+Locations{get;set;}
}|209888|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|U|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|V|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|W|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|P|5|J|7|Y|8|@]|9|@]|A|$K|L]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

hmmm, Following may help.

I was getting the same exception, and in my case I was passing the actual poco entity created for entity code first. Since, it contains relation with other entities, I just created the viewmapper/dto entity on top of it to return. 

It works fine now.

Poco Entity:

<pre><code>public class Tag
{
public int Id{get;set;}
public string Title{get;set;}
public IList&lt;Location&gt; Locations{get;set;}
}
</code></pre>

ViewMapper/Dto

<pre><code>public class TagResultsViewMapper
{
public int Id{get;set;}
public string Title{get;set;}
//just remove the following relationship 
//public IList&lt;Location&gt; Locations{get;set;}
}
</code></pre>

blocks|key|3068131|text|但是如果你在其他实体/类中发现了这个问题，你必须为每个类创建一个新的DTO，如果你有很多这样的实体/类，你可以找到一个问题，而且我认为只为解决这个问题而创建一个DTO不是最好的方法……|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3068132|你试过这个吗？|3068133|var+json+=+GlobalConfiguration.Configuration.Formatters.JsonFormatter;
json.SerializerSettings.PreserveReferencesHandling+=+
Newtonsoft.Json.PreserveReferencesHandling.All;|code-block|syntax|javascript|3068134|问候|3068135|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|O|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

but if you found this problem with other entities/classes, you have to create a new DTO for each class, and if you have a lot of them, you can find a problem, also I think that create a DTO only for solving this problem is no the best way...

Did you try this?

<pre><code>var json = GlobalConfiguration.Configuration.Formatters.JsonFormatter;
json.SerializerSettings.PreserveReferencesHandling = 
Newtonsoft.Json.PreserveReferencesHandling.All;
</code></pre>

Regards

blocks|key|213103|text|你的问题和我的很相似。不能直接从数据库返回数据。为此，您必须创建要显示的模型和关联数据。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|213104|在我示例中，有一些关于用户的数据是Json无法序列化的，我创建了一个userModel，在我的API中，我返回了userModel，而不是数据库中的用户。|213105|在用户和UserModel之间转换或关联数据的逻辑必须在API中。|213106|Failed+to+serialize+the+response+in+Web+API+with+Json|offset|length|213107|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/23098191/failed-to-serialize-the-response-in-web-api-with-json^0|0|0|0|0|1H|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|T|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|U|8|@]|9|@$H|V|I|W|1|X]]|A|$]]|$1|J|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|Q]]]]

Your question is quite similar to mine. You must not return data from database directly. For this, you must create Model and associate data you want show. 

In my example, There are data about User that Json couldn't serialize, I had create a userModel and, in my API, I return userModel instead User from database. 

The logic of convert or associate data between User and UserModel must be in API. 

<a href="https://stackoverflow.com/questions/23098191/failed-to-serialize-the-response-in-web-api-with-json">Failed to serialize the response in Web API with Json</a>

blocks|key|214523|text|这是我从odata+Web+API调用中返回的具体错误：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|214524|The+'ObjectContent`1'+type+failed+to+serialize+the+response+
body+for+content+type+'application/json;+odata.metadata=minimal'.|code-block|syntax|javascript|214525|我最终发现我的dbContext类在onModelCreating中分配了一个格式不佳的表名。所以SqlClient在寻找一个在我的db中不存在的表时要死了！！|offset|length|style|BOLD|214526|entityMap^0|0|0|21|7|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

This was the specific error I was getting back from my odata Web API call:

<pre><code>The 'ObjectContent`1' type failed to serialize the response 
body for content type 'application/json; odata.metadata=minimal'.
</code></pre>

I finally figured out that my dbContext class had a poorly formatted table name being assigned in onModelCreating.. so the SqlClient was dying looking for a table that didn't exist in my db!!

I was working on ASP.NET MVC web API, I'm having this error:

<blockquote>
 The 'ObjectContent`1' type failed to serialize the response body for content type 'application/xml; charset=utf-8'.
</blockquote>

My controller is:

<pre><code>public Employee GetEmployees()
{
 Employee employees = db.Employees.First();
 return employees;
}
</code></pre>

why I m getting this error?

failed to serialize the response in Web API

数据库

JSON

我正在开发ASP.NET MVC web API，我遇到了这个错误： 'ObjectContent`1‘类型无法序列化内容类型'application/xml；charset=utf-8’的响应正文。我的控制器是：public Employee GetEmployees(){    Employee employees = db.Employees.First();    return emplo

问无法在Web API中序列化响应
EN

回答 15

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问无法在Web API中序列化响应EN

回答 15

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问无法在Web API中序列化响应
EN