.net core 2.1 can't reference automapper in startup.cs

Question

In my nugent panel, I installed

AutoMapper v7.0.1 AutoMapper.extensions.microsoft.dependencyinjection v5.0.1

In my Startup.cs,

I added

Services.AddAutoMapper();

but the compiler gives

Severity    Code    Description Project File    Line    Suppression State
Error   CS1061  'IServiceCollection' does not contain a definition for 'AddAutoMapper' and no accessible extension method 'AddAutoMapper' accepting a first argument of type 'IServiceCollection' could be found (are you missing a using directive or an assembly reference?)  OPEApiService   J:\Projects\OPEApiService\OPEApiService\Startup.cs  58  Active

I tried clean, rebuild, close and reopen VS.

Any help is appreciated.

Thanks

duplicate https://stackoverflow.com/questions/50411188/trying-to-add-automapper-to-asp-net-core-2][1] — Mohamad Al Asmar, Feb 13 '20 at 09:56
There is a duplicate item answered below: [Trying to add AutoMapper to Asp.net Core 2?](https://stackoverflow.com/questions/50411188/trying-to-add-automapper-to-asp-net-core-2) — Mohamad Al Asmar, Feb 13 '20 at 09:57

score 8 · Answer 1 · answered Nov 16 '20 at 17:07

This could be a compatibility issue between the two packages. If you have both the AutoMapper and AutoMapper.extensions.microsoft.dependencyinjection packages installed, remove them and add only the AutoMapper.extensions.microsoft.dependencyinjection. It has a dependency on the AutoMapper package.

I had this same issue and was able to resolve it.

score 2 · Answer 2 · edited Dec 26 '22 at 04:31

2

You need to add a reference to :

$ AutoMapper.Extensions.Microsoft.DependencyInjection

Search it using NuGet Packages Manager and install it.

edited Dec 26 '22 at 04:31

Suraj Rao

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answered Dec 26 '22 at 03:56

Shalim Ahmed

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score 1 · Answer 3 · edited Oct 18 '18 at 15:49

1

You missed the restore step. From the root directory where the solution file exists, run following command:

dotnet clean
dotnet restore
dotnet build

Build error I received after including the services.AddAutoMapper();

Then after executing the series of command, got it running.

edited Oct 18 '18 at 15:49

Greenonline

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answered Oct 18 '18 at 13:24

Nishank

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.net core 2.1 can't reference automapper in startup.cs

3 Answers3