在 Visual Studio 2017 的 IServiceCollection 中找不到 AddMvc()

Question

I have created a brand new asp.net core application. I have added the mvc Nuget package yet I am getting the below error.

Microsoft.AspNetCore.Mvc.Core 1.1.3

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

Answer 1

Install-Package Microsoft.AspNetCore.Mvc -Version 1.1.3

--Update

Unload the project and Reload it again (restart)

Answer 2

Try restarting visual studio 2017.

Sounds dumb I know, but it worked for me. I added Microsoft.AspNetCore.Mvc, but Visual Studio still told me that "IServiceCollection does not contain a definition for AddMvc ...". I shutdown and restarted visual studio 2017 and the error message went away. Visual Studio 2017 is new and still seems to be a bit flaky, particularly with packages. Hopefully this will get fixed in a future update. Right Microsoft?

Answer 3

Uninstall any version of MVC from "Manage NuGet Package" window. Add this <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.3" /> to "yourprojectname.csproj" file manually. It seems the problem is related to the version of the package.

Answer 4

在 VS 2015 ASP.Net Core 1.0 项目的Startup.cs dependencies部分中使用"Microsoft.AspNetCore.Mvc": "1.0.1" 。

Answer 5

我认为，AddMvc 改为 AddMvcCore()

Answer 6

please add references

<PackageReference Include="Microsoft.AspNetCore" Version="2.2.0" />
<PackageReference Include="Microsoft.AspNetCore.CookiePolicy" Version="2.2.0" />
<PackageReference Include="Microsoft.AspNetCore.HttpsPolicy" Version="2.2.0" />
<PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.2.0" />
<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.2.0" />

in your projectname.csproj file

Answer 7

I just had the same error with visual studio 2017 when trying an 'Empty Project' (aspnet core 1.1 templates) template when creating an 'Asp.Net Core Web Application'.

Installing the latest 'Microsoft.AspNetCore.Mvc' on Nuget (version 2.2.0) failed with the message 'Package restore failed'. But installing a specific version (1.1.8) and reloading project (see Ahmed Al Jabri's answer above) fixed my error.