如何在C＃asp.net MVC中扩展RecursionLimit的限制

Question

in ASP.NET MVC i got the exception RecursionLimit exceeded when i try to sent the data to browser through JSON.

how i can make it work no matter how much big JSON is.

Answer 1

The default value of the RecursionLimit property is 100, which means that it can serialise objects that are nested to a depth of 100 objects referencing each other.

I can't imagine that you actually have objects that are nested that deep, so the most likely reason for the error message is that you have an object that contains a reference to itself, or two objects that have references to each other. As that causes an infinite chain of child objects, you get the equivalent of a stack overflow in the serialiser.

Answer 2

Use view models to break the recursion. You cannot JSON serialize objects that are recursively referencing themselves. Ayende Rahien has a nice series of blog posts about this issue.

Answer 3

You can JSON Serialize objects that are recursively referencing themselves as you Ignore those Properties. My Users Class has a Property that also is a User Object, but I ignore that Property doing:

    Users oSuperior;
    [ScriptIgnore(), XmlIgnore()]
    public Users Superior
    {
        get
        {

            if (oSuperior == null)
            {
                oSuperior = new Users();

                if (iIDUserSuperior > 0)
                    oSuperior.Load(iIDUserSuperior);
            }
            return oSuperior;
        }
    }

Answer 4

It seems that Microsoft has added some helpful properties to the JsonResult Class for increasing the recursion limit and maximum JSON length in the .NET framework 4.5 :

public ActionResult GetJson()
{
    var result = Json(obj);
    result.RecursionLimit = 1024;
    result.MaxJsonLength = 8388608;
    return result;
}

Hence, now you can easily set how "big" you want to allow your JSON objects to be by setting those properties.

Answer 5

Since the following configuration seems to be useless in ASP.NET MVC:

<system.web.extensions>
  <scripting>
    <webServices>
      <jsonSerialization recursionLimit="1024"/>
    </webServices>
  </scripting>
</system.web.extensions>

I ended up using the following one liner to solve my problem:

new System.Web.Script.Serialization.JavaScriptSerializer(){RecursionLimit = 1024}.Serialize(@Model)

Instead of using MVC's serialization method which has a default recursion limit of 100:

Json.Encode(@Model)

It may not be the best solution, but it sure is simple to use in case you need a quick fix.

Answer 6

Besides aforementioned methods, you can replace the default JSON serialization with that provided by Json.NET which by default does not seem to have an explicit limit :

A null value means there is no maximum. The default value is null.

Eg:

JsonConvert.SerializeObject(theObject);

NOTE: ASP.NET Web API uses this JSON serializer by default .