Aspnetcore: In Blazor App Client don't find "@using Microsoft.AspNetCore.Components.Authorization"

[parad74]

Describe the bug

In project Blazor Client ( TargetFramework netstandard2.0) with
PackageReference Include="Microsoft.AspNetCore.Authorization" Version="3.0.0-preview9.19424.4"
dont't find AuthenticationStateProvider => don't see namespace Microsoft.AspNetCore.Components.Authorization

if I change TargetFramework to netcoreapp3.0
I see namespace Microsoft.AspNetCore.Components.Authorization

To Reproduce

I created new simple project Blazor WebAssebly App
added Microsoft.AspNetCore.Authorization

> <Project Sdk="Microsoft.NET.Sdk.Web">
> 
>   <PropertyGroup>
>     <TargetFramework>netstandard2.0</TargetFramework>
>     <OutputType>Exe</OutputType>
>     <LangVersion>7.3</LangVersion>
>     <RazorLangVersion>3.0</RazorLangVersion>
>   </PropertyGroup>
> 
>   <ItemGroup>
>     <PackageReference Include="Microsoft.AspNetCore.Authorization" Version="3.0.0-preview9.19424.4" />
>     <PackageReference Include="Microsoft.AspNetCore.Blazor" Version="3.0.0-preview9.19424.4" />
>     <PackageReference Include="Microsoft.AspNetCore.Blazor.Build" Version="3.0.0-preview9.19424.4" PrivateAssets="all" />
>     <PackageReference Include="Microsoft.AspNetCore.Blazor.HttpClient" Version="3.0.0-preview9.19424.4" />
>     <PackageReference Include="Microsoft.AspNetCore.Blazor.DevServer" Version="3.0.0-preview9.19424.4" PrivateAssets="all" />
>   </ItemGroup>
> 
> </Project>

1. See error
   @using Microsoft.AspNetCore.Components.Authorization show red

Error CS0234 The type or namespace name 'Authorization' does not exist in the namespace 'Microsoft.AspNetCore.Components' (are you missing an assembly reference?) BlazorAppClient5 C:\Users\Пользователь\source\repos\BlazorAppClient5\BlazorAppClient5_Imports.razor

[jucchytil]

I second this one. I was using AuthenticationStateProvider fine on P8 yesterday morning.
P9 broke it.

Creating client-side and server-side default apps and adding an @import to the MainLayout.razor file. I browsed all the available namespaces on the client-side app and could not find the AuthenticationStateProvider class but on the server-side app, it is found in the Microsoft.AspNetCore.Components.Authorization namespace.

This namespace does not exist on the client-side app.

The server-side csproj file refers to the target framework netcoreapp3.0 with no additional project references.

The client-side csproj file refers to target framework netstandard2.0 and the project references

• "Microsoft.AspNetCore.Blazor" Version="3.0.0-preview9.19424.4"
• "Microsoft.AspNetCore.Blazor.Build" Version="3.0.0-preview9.19424.4" PrivateAssets="all"
• "Microsoft.AspNetCore.Blazor.HttpClient" Version="3.0.0-preview9.19424.4"
• "Microsoft.AspNetCore.Blazor.DevServer" Version="3.0.0-preview9.19424.4" PrivateAssets="all"

Is it still possible for client-side developers to get access to the Microsoft.AspNetCore.Components.Authorization namespace?

[ghidello]

Try adding the reference explicitly using
Install-Package Microsoft.AspNetCore.Components.Authorization -Version 3.0.0-preview9.19424.4

[jucchytil]

Thanks! That worked!

[parad74]

thanks, it works for me !

[mkArtakMSFT]

Thanks @ghidello.
We will include this in the migration guide to help the rest of the community with this.
/cc @danroth27

[dynamiclynk]

These aren't showing in the VS nuget feed at least at the time of this post.

[campersau]

It is in there, but the updated NuGet search puts it way back... The easiest is to add it manually into the csproj.

[danroth27]

With NuGet search if you want to search by package ID you can add the "packageid:" prefix. See https://github.com/aspnet/AspNetCore/issues/13499#issuecomment-525896607.

[MV10]

That updated NuGet search is awful... who the heck thought exact matches shouldn't show up first?!

[VWilcox2000]

Weird thing is it builds fine on local machine, but not on build server -- that's frustrating... but more frustrating is that NuGet search (agree @MV10)!!!!!! It's like they put in the most intelligent contextual search system they possibly could... then accidentally listed it backwards.