blocks|key|3242495|text|我刚刚在Parent/Child集合中遇到了同样的问题，并找到了解决我问题的那篇文章。我只想显示父集合项目的列表，不需要任何子数据，因此我使用了以下内容，它工作得很好：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3242496|JsonConvert.SerializeObject(ResultGroups,+Formatting.None,
++++++++++++++++++++++++new+JsonSerializerSettings()
++++++++++++++++++++++++{+
++++++++++++++++++++++++++++ReferenceLoopHandling+=+ReferenceLoopHandling.Ignore
++++++++++++++++++++++++});|code-block|syntax|javascript|3242497|JSON.NET+Error+Self+referencing+loop+detected+for+type|offset|length|3242498|它还引用了位于以下位置的Json.NET+Codeplex页：|3242499|http://json.codeplex.com/discussions/272371|3242500|文档：|3242501|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/7397207/json-net-error-self-referencing-loop-detected-for-type|1^0|0|0|0|1I|0|0|0|0|17|1|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|10|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|11|8|@]|9|@$I|12|J|13|1|14]]|A|$]]|$1|K|3|L|5|6|7|15|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|16|8|@]|9|@$I|17|J|18|1|19]]|A|$]]|$1|O|3|P|5|6|7|1A|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|R|$S|$5|T|U|V|A|$W|X]]|Y|$5|T|U|V|A|$W|N]]]]

I just had the same problem with Parent/Child collections and found that post which has solved my case. 
I Only wanted to show the List of parent collection items and didn't need any of the child data, therefore i used the following and it worked fine:

<pre><code>JsonConvert.SerializeObject(ResultGroups, Formatting.None,
 new JsonSerializerSettings()
 { 
 ReferenceLoopHandling = ReferenceLoopHandling.Ignore
 });
</code></pre>

<a href="https://stackoverflow.com/questions/7397207/json-net-error-self-referencing-loop-detected-for-type">JSON.NET Error Self referencing loop detected for type</a>

it also referes to the Json.NET codeplex page at: 

<a href="http://json.codeplex.com/discussions/272371" rel="noreferrer">http://json.codeplex.com/discussions/272371</a>

Documentation: <a href="http://www.newtonsoft.com/json/help/html/ReferenceLoopHandlingIgnore.htm" rel="noreferrer">ReferenceLoopHandling setting</a>

blocks|key|3242536|text|修复方法是忽略循环引用，并且不序列化它们。此行为在JsonSerializerSettings中指定。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3242537|具有过载的Single+JsonConvert：|BOLD|3242538|JsonConvert.SerializeObject((from+a+in+db.Events+where+a.Active+select+a).ToList(),+Formatting.Indented,
++++new+JsonSerializerSettings()+{
++++++++ReferenceLoopHandling+=+Newtonsoft.Json.ReferenceLoopHandling.Ignore
++++}
);|code-block|syntax|javascript|3242539|如果您想将其设置为默认行为，请添加一个全局设置，其代码为Global.asax.cs中的Application_Start()：|3242540|JsonConvert.DefaultSettings+=+()+=>+new+JsonSerializerSettings+{
+++++Formatting+=+Newtonsoft.Json.Formatting.Indented,
+++++ReferenceLoopHandling+=+Newtonsoft.Json.ReferenceLoopHandling.Ignore
};|3242541|参考：https://github.com/JamesNK/Newtonsoft.Json/issues/78|3242542|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/JamesNK/Newtonsoft.Json/issues/78^0|P|M|0|5|6|C|B|C|B|0|0|J|4|18|J|0|0|3|1G|0|0^^$0|@$1|2|3|4|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|14|8|@$9|15|A|16|B|H]|$9|17|A|18|B|H]|$9|19|A|1A|B|C]]|D|@]|E|$]]|$1|I|3|J|5|K|7|1B|8|@]|D|@]|E|$L|M]]|$1|N|3|O|5|6|7|1C|8|@$9|1D|A|1E|B|H]|$9|1F|A|1G|B|C]]|D|@]|E|$]]|$1|P|3|Q|5|K|7|1H|8|@]|D|@]|E|$L|M]]|$1|R|3|S|5|6|7|1I|8|@]|D|@$9|1J|A|1K|1|1L]]|E|$]]|$1|T|3|-4|5|6|7|1M|8|@]|D|@]|E|$]]]|U|$V|$5|W|X|Y|E|$Z|10]]]]

The fix is to ignore loop references and not to serialize them. This behaviour is specified in <code>JsonSerializerSettings</code>.

Single <code>JsonConvert</code> with an overload:

<pre class="lang-cs prettyprint-override"><code>JsonConvert.SerializeObject((from a in db.Events where a.Active select a).ToList(), Formatting.Indented,
 new JsonSerializerSettings() {
 ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore
 }
);
</code></pre>

If you'd like to make this the default behaviour, add a 
Global Setting with code in <code>Application_Start()</code> in Global.asax.cs:

<pre class="lang-cs prettyprint-override"><code>JsonConvert.DefaultSettings = () =&gt; new JsonSerializerSettings {
 Formatting = Newtonsoft.Json.Formatting.Indented,
 ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore
};
</code></pre>

Reference: <a href="https://github.com/JamesNK/Newtonsoft.Json/issues/78" rel="noreferrer">https://github.com/JamesNK/Newtonsoft.Json/issues/78</a>

blocks|key|3455529|text|这可能会对你有帮助。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3455530|public+MyContext()+:+base("name=MyContext")+
{+
++++Database.SetInitializer(new+MyContextDataInitializer());+
++++this.Configuration.LazyLoadingEnabled+=+false;+
++++this.Configuration.ProxyCreationEnabled+=+false;+
}+|code-block|syntax|javascript|3455531|http://code.msdn.microsoft.com/Loop-Reference-handling-in-caaffaf7|offset|length|3455532|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|1U|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|T|8|@]|9|@$I|U|J|V|1|W]]|A|$]]|$1|K|3|-4|5|6|7|X|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|H]]]]

This may help you.

<pre><code>public MyContext() : base("name=MyContext") 
{ 
 Database.SetInitializer(new MyContextDataInitializer()); 
 this.Configuration.LazyLoadingEnabled = false; 
 this.Configuration.ProxyCreationEnabled = false; 
} 
</code></pre>

<a href="http://code.msdn.microsoft.com/Loop-Reference-handling-in-caaffaf7">http://code.msdn.microsoft.com/Loop-Reference-handling-in-caaffaf7</a>

blocks|key|407615|text|如果使用ASP.NET核心MVC，请将以下代码添加到startup.cs文件的ConfigureServices方法中：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|407616|services.AddMvc()
++++.AddJsonOptions(
++++++++options+=>+options.SerializerSettings.ReferenceLoopHandling+=++++++++++++
++++++++Newtonsoft.Json.ReferenceLoopHandling.Ignore
++++);|code-block|syntax|javascript|407617|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|$]]

If using ASP.NET Core MVC, add this to the ConfigureServices method of your startup.cs file:

<pre><code>services.AddMvc()
 .AddJsonOptions(
 options =&gt; options.SerializerSettings.ReferenceLoopHandling = 
 Newtonsoft.Json.ReferenceLoopHandling.Ignore
 );
</code></pre>

blocks|key|3242602|text|您必须设置保留对象引用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3242603|var+jsonSerializerSettings+=+new+JsonSerializerSettings
{
++++PreserveReferencesHandling+=+PreserveReferencesHandling.Objects
};|code-block|syntax|javascript|3242604|然后调用查询var+q+=+(from+a+in+db.Events+where+a.Active+select+a).ToList();，如下所示|offset|length|style|CODE|3242605|3242606|+string+jsonStr+=+Newtonsoft.Json.JsonConvert.SerializeObject(q,+jsonSerializerSettings);|blockquote|3242607|3242608|3242609|请参阅：https://www.newtonsoft.com/json/help/html/PreserveObjectReferences.htm|3242610|entityMap|0|LINK|mutability|MUTABLE|url|https://www.newtonsoft.com/json/help/html/PreserveObjectReferences.htm^0|0|0|6|1R|0|0|1|2G|0|0|0|4|1Y|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|14|8|@$I|15|J|16|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|17|8|@]|9|@]|A|$]]|$1|N|3|O|5|P|7|18|8|@$I|19|J|1A|K|L]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]|$1|R|3|-4|5|6|7|1C|8|@]|9|@]|A|$]]|$1|S|3|T|5|6|7|1D|8|@]|9|@$I|1E|J|1F|1|1G]]|A|$]]|$1|U|3|-4|5|6|7|1H|8|@]|9|@]|A|$]]]|V|$W|$5|X|Y|Z|A|$10|11]]]]

You must set Preserving Object References:

<pre><code>var jsonSerializerSettings = new JsonSerializerSettings
{
 PreserveReferencesHandling = PreserveReferencesHandling.Objects
};
</code></pre>

Then call your query <code>var q = (from a in db.Events where a.Active select a).ToList();</code> like 

<blockquote>
 <code>string jsonStr = Newtonsoft.Json.JsonConvert.SerializeObject(q, jsonSerializerSettings);</code>
</blockquote>

See:
<a href="https://www.newtonsoft.com/json/help/html/PreserveObjectReferences.htm" rel="nofollow noreferrer">https://www.newtonsoft.com/json/help/html/PreserveObjectReferences.htm</a>

blocks|key|407630|text|JsonConvert.SerializeObject(ObjectName,+new+JsonSerializerSettings(){+++++++++++++PreserveReferencesHandling+=+PreserveReferencesHandling.Objects,+++++++++++++Formatting+=+Formatting.Indented+++++++++});|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|407631|entityMap^0|0|5N|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

<code>JsonConvert.SerializeObject(ObjectName, new JsonSerializerSettings(){
 PreserveReferencesHandling = PreserveReferencesHandling.Objects,
 Formatting = Formatting.Indented
 });</code>

blocks|key|3455615|text|将"JsonIgnore“添加到模型类中|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3455616|{
++public+Customer()
++{
++++Orders+=+new+Collection<Order>();
++}

public+int+Id+{+get;+set;+}
public+string+Name+{+get;+set;+}
public+string+Surname+{+get;+set;+}

[JsonIgnore]
public+ICollection<Order>+Orders+{+get;+set;+}
}|code-block|syntax|javascript|3455617|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|$]]

Add "[JsonIgnore]" to your model class 

<pre><code>{
 public Customer()
 {
 Orders = new Collection&lt;Order&gt;();
 }

public int Id { get; set; }
public string Name { get; set; }
public string Surname { get; set; }

[JsonIgnore]
public ICollection&lt;Order&gt; Orders { get; set; }
}
</code></pre>

blocks|key|407697|text|我正在使用Dot.Net+Core3.1，并搜索了|type|unstyled|depth|inlineStyleRanges|entityRanges|data|407698|407699|+"Newtonsoft.Json.JsonSerializationException:检测到属性的自引用循环"|blockquote|407700|407701|我将这个问题添加到这个问题中，因为它将是一个简单的参考。您应该在Startup.cs文件中使用以下内容：|407702|+services.AddControllers()
++++++++++++++++.AddNewtonsoftJson(options+=>
++++++++++++++++{
++++++++++++++++++++//+Use+the+default+property+(Pascal)+casing
++++++++++++++++++++options.SerializerSettings.ContractResolver+=+new+CamelCasePropertyNamesContractResolver();
++++++++++++++++++++options.SerializerSettings.ReferenceLoopHandling+=+ReferenceLoopHandling.Ignore;
++++++++++++++++});|code-block|syntax|javascript|407703|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|R|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|T|8|@]|9|@]|A|$]]|$1|I|3|J|5|K|7|U|8|@]|9|@]|A|$L|M]]|$1|N|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|O|$]]

I am using Dot.Net Core 3.1 and did an search for

<blockquote>
 <blockquote>
 "Newtonsoft.Json.JsonSerializationException: Self referencing loop detected for property "
 </blockquote>
</blockquote>

I am adding this to this question, as it will be an easy reference. 
You should use the following in the Startup.cs file:

<pre><code> services.AddControllers()
 .AddNewtonsoftJson(options =&gt;
 {
 // Use the default property (Pascal) casing
 options.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
 options.SerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
 });
</code></pre>

blocks|key|404340|text|有时会出现循环，因为您的类型类引用了其他类，而这些类又引用了您的类型类，因此您必须在json字符串中选择所需的参数，如下面的代码所示。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|404341|List<ROficina>+oficinas+=+new+List<ROficina>();
oficinas+=+/*list+content*/;
var+x+=+JsonConvert.SerializeObject(oficinas.Select(o+=>+new
++++++++++++{
++++++++++++++++o.IdOficina,
++++++++++++++++o.Nombre
++++++++++++}));|code-block|syntax|javascript|404342|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|$]]

Sometimes you have loops becouse your type class have references to other classes and that classes have references to your type class, thus you have to select the parameters that you need exactly in the json string, like this code.

<pre><code>List&lt;ROficina&gt; oficinas = new List&lt;ROficina&gt;();
oficinas = /*list content*/;
var x = JsonConvert.SerializeObject(oficinas.Select(o =&gt; new
 {
 o.IdOficina,
 o.Nombre
 }));
</code></pre>

blocks|key|407705|text|对于asp.net核心3.1.3，这对我来说很有效|type|unstyled|depth|inlineStyleRanges|entityRanges|data|407706|services.AddControllers().AddNewtonsoftJson(opt=>{
++++++++++++opt.SerializerSettings.ReferenceLoopHandling+=+Newtonsoft.Json.ReferenceLoopHandling.Ignore;
++++++++});|code-block|syntax|javascript|407707|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|$]]

for asp.net core 3.1.3 this worked for me
<pre><code>services.AddControllers().AddNewtonsoftJson(opt=&gt;{
 opt.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
 });
</code></pre>

blocks|key|3242651|text|可以将JsonSerializer实例配置为忽略引用循环。如下所示，此函数允许使用json序列化对象的内容保存文件：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3242652|++++public+static+void+SaveJson<T>(this+T+obj,+string+FileName)
++++{
+++
+++++++JsonSerializer+serializer+=+new+JsonSerializer();
++++++++serializer.ReferenceLoopHandling+=+ReferenceLoopHandling.Ignore;
++++++++using+(StreamWriter+sw+=+new+StreamWriter(FileName))
++++++++{
++++++++++++using+(JsonWriter+writer+=+new+JsonTextWriter(sw))
++++++++++++{
++++++++++++++++writer.Formatting+=+Formatting.Indented;
++++++++++++++++serializer.Serialize(writer,+obj);
++++++++++++}
++++++++}
++++}|code-block|syntax|javascript|3242653|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|$]]

The JsonSerializer instance can be configured to ignore reference loops. Like in the following, this function allows to save a file with the content of the json serialized object:
<pre><code> public static void SaveJson&lt;T&gt;(this T obj, string FileName)
 {
 
 JsonSerializer serializer = new JsonSerializer();
 serializer.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
 using (StreamWriter sw = new StreamWriter(FileName))
 {
 using (JsonWriter writer = new JsonTextWriter(sw))
 {
 writer.Formatting = Formatting.Indented;
 serializer.Serialize(writer, obj);
 }
 }
 }
</code></pre>

I have a mssql database for my website within 4 tables.

When I use this:

<pre><code>public static string GetAllEventsForJSON()
{
 using (CyberDBDataContext db = new CyberDBDataContext())
 {
 return JsonConvert.SerializeObject((from a in db.Events where a.Active select a).ToList(), new JavaScriptDateTimeConverter());
 }
}
</code></pre>

The code results in the following error:

<blockquote>
 Newtonsoft.Json.JsonSerializationException: Self referencing loop detected for property 'CyberUser' with type 'DAL.CyberUser'.
 Path '[0].EventRegistrations[0].CyberUser.UserLogs[0]'.
</blockquote>

JSON.Net Self referencing loop detected

数据库

我有一个mssql数据库为我的网站在4个表。当我使用这个的时候：public static string GetAllEventsForJSON(){    using (CyberDBDataContext db = new CyberDBDataContext())    {        return JsonC...

问检测到JSON.Net自引用循环
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