'IServiceCollection' does not contain a definition for 'AddSession' [duplicate]

13
votes

I am getting an error while adding 'AddSession' in ASP.Net Core 1.1 using VS2017.

'IServiceCollection' does not contain a definition for 'AddSession' and no extension method 'AddSession' accepting a first argument of type 'IServiceCollection' could be found (are you missing a using directive or an assembly reference?)

.csproj

<Project Sdk="Microsoft.NET.Sdk.Web">

<PropertyGroup>
<TargetFramework>netcoreapp1.1</TargetFramework>
</PropertyGroup>

<PropertyGroup>
<PackageTargetFallback>$(PackageTargetFallback);portable-net45+win8+wp8+wpa81;</PackageTargetFallback>
</PropertyGroup>
 <ItemGroup>
  <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.0.0" />
  <PackageReference Include="Microsoft.AspNetCore" Version="1.1.1" />
<PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.Session" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="1.1.1" />
<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="1.1.1" />
<PackageReference Include="Microsoft.VisualStudio.Web.BrowserLink" Version="1.1.0" />
 </ItemGroup>
 <ItemGroup>
 <DotNetCliToolReference 
 Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="1.0.0" />
</ItemGroup>

 </Project>

Error :

enter image description here

7
sessionasp.net-coreasp.net-core-1.0asp.net-core-1.1visual-studio-2017
Building seems to work fine. Visual Studio might just be off here, did you try to restart it? – Henk Mollema
@HenkMollema Yes, It's throwing the same issue. – Rajeesh Menoth
Well-known problem. Try stackoverflow.com/a/43562917/5112433 – Ilya Chumakov
Now it's working !! I just restarted my machine. – Rajeesh Menoth
@llya Chumakov well known yet ignored by microsoft – JSON

7 Answers

13
votes

I know this is a bit late, but did you try to install the Microsoft.AspNetCore.Session package from nuget?

https://www.nuget.org/packages/Microsoft.AspNetCore.Session/

In Visual Studio: Install-Package Microsoft.AspNetCore.Session -Version 1.1.2(in my case)

It worked for me!

8
votes

The following way I fixed the Issue.

  1. Clean and Rebuild the solution.
  2. Restart Visual Studio 2017.

Thanks @HenkMollema

5
votes

The versions of the dependencies seem to be out of sync. Use Nuget to update all your packages to be the same version and that should solve the issue. This applies to most if not all Microsoft.* packages.

Also you need the following using statements:

using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;
using System;
2
votes

Make sure you have

<PackageReference Include="Microsoft.AspNetCore.Session" Vesion="1.1.1" />

(or more up-to-date version) within your .csproj file.

0
votes

In my case AutoMapper.Extensions.Microsoft.DependencyInjection (v1 was installed). Uninstalled and installed AutoMapper.Extensions.Microsoft.DependencyInjection v5.0.1

0
votes

It looks like you missed something. In Package Manager Console, write:

install-package Microsoft.AspNetCore.Session -version x.x.x

x.x.x depends on your project reference

0
votes

Run the below command in your package manager console

Install-Package AutoMapper.Extensions.Microsoft.DependencyInjection