I’m always forgetting which return types are available directly from ASP.Net controllers, so have created a quick listing here.

For general information on HTTP Status codes see
https://en.wikipedia.org/wiki/List_of_HTTP_status_codes

ASP.Net Core 2.2

All Status Codes:

https://docs.microsoft.com/en-gb/dotnet/api/microsoft.aspnetcore.http.statuscodes?view=aspnetcore-2.2

ControllerBase IActionResult Return Types

• OK (200)
• BadRequest (400)
• Forbid (403)
• LocalRedirect (302)
• LocalRedirectPermanent (301)
• LocalRedirectPermanentPreserve (308)
• LocalRedirectPermanentPreserveMethod (307)
• NoContent (204)
• NotFound (404)
• RedirectToAction (302)
• RedirectToActionPermanent (301)
• RedirectToActionPermanentPreserve (308)
• RedirectToActionPermanentPreserveMethod (307)
• RedirectToPage (302)
• RedirectToPagePermanent (301)
• RedirectToPagePermanentPreserve (308)
• RedirectToPagePermanentPreserveMethod (307)
• RedirectToPage (302)
• RedirectToPagePermanent (301)
• RedirectToPagePermanentPreserve (308)
• RedirectToPagePermanentPreserveMethod (307)
• StatusCode (set own status code)
  • Use 409 – Conflict, for updates that fail due to conflicts such as already exists etc..
• Unauthorized (401)
• UnprocessableEntity (422)
• ValidationProblem (400)

ApiController MVC Compatibility Shim

https://docs.microsoft.com/en-us/dotnet/api/system.web.http.apicontroller?view=aspnetcore-2.2

• OK (200)
• BadRequest (400)
• Conflict (409)
• Created (201)
• CreatedAtRoute (201)
• InternalServerError (500)
• NotFound (404)
• Redirect (302)
• RedirectToRoute (302)
• StatusCode (set own status code)
  • Use 409 – Conflict, for updates that fail due to conflicts such as already exists etc..
• Unauthorized (401)
• UnprocessableEntity (422)
• ValidationProblem (400)