How to set custom JsonSerializerSettings for Json.NET in ASP.NET Web API?

Question

I understand that ASP.NET Web API natively uses Json.NET for (de)serializing objects, but is there a way to specify a JsonSerializerSettings object that you want for it to use?

For example, what if I wanted to include type information into the serialized JSON string? Normally I'd inject settings into the .Serialize() call, but Web API does that silently. I can't find a way to inject settings manually.

Answer 1

You can customize the JsonSerializerSettings by using the Formatters.JsonFormatter.SerializerSettings property in the HttpConfiguration object.

For example, you could do that in the Application_Start() method:

protected void Application_Start() {     HttpConfiguration config = GlobalConfiguration.Configuration;     config.Formatters.JsonFormatter.SerializerSettings.Formatting =         Newtonsoft.Json.Formatting.Indented; } 

Answer 2

You can specify JsonSerializerSettings for each JsonConvert, and you can set a global default.

Single JsonConvert with an overload:

// Option #1. JsonSerializerSettings config = new JsonSerializerSettings { ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore }; this.json = JsonConvert.SerializeObject(YourObject, Formatting.Indented, config);  // Option #2 (inline). JsonConvert.SerializeObject(YourObject, Formatting.Indented,     new JsonSerializerSettings() {         ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore     } ); 

Global Setting with code in Application_Start() in Global.asax.cs:

JsonConvert.DefaultSettings = () => new JsonSerializerSettings {      Formatting = Newtonsoft.Json.Formatting.Indented,      ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore }; 

Reference: https://github.com/JamesNK/Newtonsoft.Json/issues/78