IResult (from Asp) not found in standard 2.0 project

Question

I created a DLL project targeting .net standard 2.0.

With NuGet I added a reference to Microfosft.AspNetCore.Http. (2.2.2)

I created this class:

using System;
using Microsoft.AspNetCore.Http;

namespace netstdlib
{
   public class Class1
   {
      public IResult DoGet()
      {
         return null;
      }
   }
}

When I build I get

Build started...
1>------ Build started: Project: netstdlib, Configuration: Debug Any CPU ------
1>D:\PROJECTS\experiment\CS framework test\netstdlib\Class1.cs(10,25,10,32): error CS0246: 
  The type or namespace name 'IResult' could not be found (are you missing a using 
  directive or an assembly reference?)
1>Done building project "netstdlib.csproj" -- FAILED.
========== Build: 0 succeeded, 1 failed, 2 up-to-date, 0 skipped ==========

It seems to me it should find IResult in the library I'm using. What's wrong?

score 1 · Answer 1 · answered May 04 '22 at 13:37

1

The IResult interface in the Microsoft.AspNetCore.Http namespace was added in ASP.NET Core 6, so you need to update if you want to use it.

See documentation: IResult Interface.

answered May 04 '22 at 13:37

Camilo Terevinto

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This is not a question of Update. Standard is required for a library that's used by both Framework and Core. I need an alternative. – Alan Baljeu May 12 '22 at 12:58
@AlanBaljeu What magic alternative do you expect? You want to use something that is not supported. If you explained what you wanted to do it would be easier to help (like, why are you not using `IActionResult` instead?) – Camilo Terevinto May 12 '22 at 13:01
never head of IActionResult. I assumed there was something pre-6 but I couldn't find it. – Alan Baljeu May 12 '22 at 13:06
IActionResult is from Microsoft.AspNetCore.Mvc and has existed always in ASP.NET Core. If you don't know the framework at all, what exactly are you trying to do? – Camilo Terevinto May 12 '22 at 13:07
Trying to learn the framework to build a library that provides app-specific HTTP services that is consumable by Framework and Core environments. I only started working Http with .net6 and I needed to make some code available to a .net framework project. – Alan Baljeu May 12 '22 at 13:08
Then you should be interested in knowing that there is **no way** to share HTTP methods between ASP.NET Framework and ASP.NET Core - read on: https://stackoverflow.com/questions/47357689/httpcontext-in-net-standard-library/47357919#47357919 – Camilo Terevinto May 12 '22 at 13:12
Oh thank you very much for that pointer. That is a huge change in direction for me. – Alan Baljeu May 12 '22 at 13:17

score 0 · Accepted Answer · answered May 16 '22 at 14:31

Thanks to Camilo for pointing out why IResult can't work. I did find a way that will work:

HttpResponseMessage as produced by HttpClient.GetAsync is usable in .net core. Whether or not these classes are usable in .net framework I didn't try, but I can use HttpResponseMessage to extract data in a Standard dll, and return that data to a .net framework project.

IResult (from Asp) not found in standard 2.0 project

2 Answers2