Can I set an unlimited length for maxJsonLength in

Question

I am using the autocomplete feature of jQuery. When I try to retrieve the list of more then 17000 records (each won't have more than 10 char length), it's exceeding the length and throws the error:

Exception information:
Exception type: InvalidOperationException
Exception message: Error during serialization or deserialization using the JSON JavaScriptSerializer. The length of the string exceeds the value set on the maxJsonLength property.

Can I set an unlimited length for maxJsonLength in web.config? If not, what is the maximum length I can set?

Answer 1

I solved the problem adding this code:

String confString = HttpContext.Current.Request.ApplicationPath.ToString();
Configuration conf = WebConfigurationManager.OpenWebConfiguration(confString);
ScriptingJsonSerializationSection section = (ScriptingJsonSerializationSection)conf.GetSection("system.web.extensions/scripting/webServices/jsonSerialization");
section.MaxJsonLength = 6553600;
conf.Save();

Answer 2

If you are encountering this sort of issue in View, you can use below method to resolve that. Here Iused Newtonsoft package .

@using Newtonsoft.Json
<script type="text/javascript">
    var partData = @Html.Raw(JsonConvert.SerializeObject(ViewBag.Part));
</script>

Answer 3

If you are using MVC 4, be sure to check out this answer as well.

---

If you are still receiving the error:

• after setting the maxJsonLength property to its maximum value in web.config
• and you know that your data's length is less than this value
• and you are not utilizing a web service method for the JavaScript serialization

your problem is is likely that:

The value of the MaxJsonLength property applies only to the internal JavaScriptSerializer instance that is used by the asynchronous communication layer to invoke Web services methods. (MSDN: ScriptingJsonSerializationSection.MaxJsonLength Property)

Basically, the "internal" JavaScriptSerializer respects the value of maxJsonLength when called from a web method; direct use of a JavaScriptSerializer (or use via an MVC action-method/Controller) does not respect the maxJsonLength property, at least not from the systemWebExtensions.scripting.webServices.jsonSerialization section of web.config.

As a workaround, you can do the following within your Controller (or anywhere really):

var serializer = new JavaScriptSerializer();

// For simplicity just use Int32's max value.
// You could always read the value from the config section mentioned above.
serializer.MaxJsonLength = Int32.MaxValue;

var resultData = new { Value = "foo", Text = "var" };
var result = new ContentResult{
    Content = serializer.Serialize(resultData),
    ContentType = "application/json"
};
return result;

---

This answer is my interpretation of this asp.net forum answer.

Answer 4

You can configure the max length for json requests in your web.config file:

<configuration>
    <system.web.extensions>
        <scripting>
            <webServices>
                <jsonSerialization maxJsonLength="....">
                </jsonSerialization>
            </webServices>
        </scripting>
    </system.web.extensions>
</configuration>

The default value for maxJsonLength is 102400. For more details, see this MSDN page: http://msdn.microsoft.com/en-us/library/bb763183.aspx

Answer 5

If you are getting this error from the MiniProfiler in MVC then you can increase the value by setting the property MiniProfiler.Settings.MaxJsonResponseSize to the desired value. By default, this tool seems to ignore the value set in config.

MiniProfiler.Settings.MaxJsonResponseSize = 104857600;

Courtesy mvc-mini-profiler.

Answer 6

if, after implementing the above addition into your web.config, you get an “Unrecognized configuration section system.web.extensions.” error then try adding this to your web.config in the <ConfigSections> section:

            <sectionGroup name="system.web.extensions" type="System.Web.Extensions">
              <sectionGroup name="scripting" type="System.Web.Extensions">
                    <sectionGroup name="webServices" type="System.Web.Extensions">
                          <section name="jsonSerialization" type="System.Web.Extensions"/>
                    </sectionGroup>
              </sectionGroup>
        </sectionGroup>