Where did IMvcBuilder AddJsonOptions go in .Net Core 3.0?

by

As part of ASP.NET Core 3.0, the team moved away from including Json.NET by default. You can read more about that in general in the announcement on breaking changes to Microsoft.AspNetCore.App.

Instead of Json.NET, ASP.NET Core 3.0 and .NET Core 3.0 include a different JSON API that focuses a bit more on performance. You can learn about that more in the announcement about “The future of JSON in .NET Core 3.0”.

The new templates for ASP.NET Core will no longer bundle with Json.NET but you can easily reconfigure the project to use it instead of the new JSON library. This is important for both compatibility with older projects and also because the new library is not supposed to be a full replacement, so you won’t see the full feature set there.

In order to reconfigure your ASP.NET Core 3.0 project with Json.NET, you will need to add a NuGet reference to Microsoft.AspNetCore.Mvc.NewtonsoftJson, which is the package that includes all the necessary bits. Then, in the Startup’s ConfigureServices, you will need to configure MVC like this:

services.AddControllers()
    .AddNewtonsoftJson();

This sets up MVC controllers and configures it to use Json.NET instead of that new API. Instead of controllers, you can also use a different MVC overload (e.g. for controllers with views, or Razor pages). That AddNewtonsoftJson method has an overload that allows you to configure the Json.NET options like you were used to with AddJsonOptions in ASP.NET Core 2.x.

services.AddControllers()
    .AddNewtonsoftJson(options =>
    {
        options.SerializerSettings.ContractResolver = new DefaultContractResolver();
    });

More Related Contents:

  1. How do I get the contents of a JSON file I added in the StartUp method to use it in one of my actions?
  2. “Self Referencing Loop Detected” exception with JSON.Net
  3. Configure the authorization server endpoint
  4. Return View as String in .NET Core
  5. ASP.NET Core: Exclude or include files on publish
  6. Json.NET serialize object with root name
  7. What is the difference between PreserveReferencesHandling and ReferenceLoopHandling in Json.Net?
  8. IdentityServer4 Role Based Authorization for Web API with ASP.NET Core Identity
  9. JsonSerializerSettings and Asp.Net Core
  10. How do I get the kestrel web server to listen to non-localhost requests?
  11. How to create roles in ASP.NET Core and assign them to users?
  12. Custom Authentication in ASP.Net-Core
  13. .NET Core 3.0: Razor views don’t automatically recompile on change
  14. .Net Core 3.0 JsonSerializer populate existing object
  15. TempData null in asp.net core
  16. Convert IHtmlContent/TagBuilder to string in C#
  17. How to set json serializer settings in asp.net core 3?
  18. System.Text.Json: Deserialize JSON with automatic casting
  19. ASP.Net Core MVC – Client-side validation for custom attribute
  20. Identity UI no longer works after switching to .net core 3 endpoint routing
  21. Identity in ASP.Net Core 2.1< - Customize AccountController
  22. Simple JWT authentication in ASP.NET Core 1.0 Web API
  23. How do I inject ASP.NET 5 (vNext) user-secrets into my own utility class?
  24. Tag helper not being processed in ASP.NET Core 2
  25. Bind Dictionary with list in viewmodel to checkboxes
  26. Dealing with large file uploads on ASP.NET Core 1.0
  27. How can I ensure that appsettings.dev.json gets copied to the output folder?
  28. Can System.Web be used with ASP.Net Core with Full Framework
  29. An error occurred attempting to determine the process id of dotnet.exe which is hosting your application. One or more error occured
  30. Unable to resolve service for type ‘Microsoft.AspNetCore.Identity.UserManager` while attempting to activate ‘AuthController’

Leave a Comment