IdentityServer4和ASP.NET Core 2.0

Question

I must be missing something but I cannot see it.
I have created a new 'empty' ASP.NET Core 2.0 Project
I added EF Core 2.0 and EF Core 2.0 Identity
I then try to add IdentityServer4 2.0 rc1 and I get a package restore failure with the following error message:

Error occurred while restoring NuGet packages: Sequence contains more than one matching element

There is no code in this project so I am completely confused.

Here is the csproj file:

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

  <PropertyGroup>
    <TargetFramework>netcoreapp2.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <Folder Include="wwwroot\" />
  </ItemGroup>

  <ItemGroup>
    <PackageReference Include="IdentityServer4" Version="2.0.0-rc1-update1" />
    <PackageReference Include="IdentityServer4.AspNetIdentity" Version="2.0.0-rc1" />
    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Authentication.Cookies" Version="2.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Authentication.OpenIdConnect" Version="2.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Identity" Version="2.0.0" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="2.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.0.0" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="2.0.0" />
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="2.0.0" />
    <PackageReference Include="NETStandard.Library" Version="2.0.0" />
  </ItemGroup>
  <ItemGroup>
    <DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="2.0.0" />
    <DotNetCliToolReference Include="Microsoft.Extensions.SecretManager.Tools" Version="2.0.0" />
    <DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="2.0.0" />
  </ItemGroup>
</Project>

Here is my call to NuGet.org from the Package Manager Console:

PM> Install-Package IdentityServer4.AspNetIdentity -Version 2.0.0-rc1 -Prerelease GET https://api.nuget.org/v3/registration3-gz-semver2/identityserver4.aspnetidentity/index.json OK https://api.nuget.org/v3/registration3-gz-semver2/identityserver4.aspnetidentity/index.json 484ms Restoring packages for D:\\ProtoTypes\\IdentityServer4\\IdentityServer4\\IdentityServer4.csproj... Install-Package : Sequence contains more than one matching element At line:1 char:1 + Install-Package IdentityServer4.AspNetIdentity -Version 2.0.0-rc1 -Pr ... + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [Install-Package], Exception + FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.InstallPackageCommand Time Elapsed: 00:00:03.7728514 PM>

Answer 1

Following are some changes that you will migrate your project to asp.net core 2.0.? Step 1: Download asp.net core 2.0 gx64x for visual studio 2017 from the following link.? https://www.microsoft.com/net/download/core ? Step 2: Download from Nuget packages or from package manager console 1-Install-Package IdentityServer4 -Version 2.0.0 2-Install-Package IdentityServer4.AspNetIdentity -Version 2.0.0-rc1-update2

Step 3: Update Some Code in Csproj file. Before: netcoreapp1.1 After: netcoreapp2.0

Before:
<PackageReference Include="Microsoft.AspNetCore.Authentication.Cookies" Version="1.1.1" />
<PackageReference Include="Microsoft.AspNetCore.Diagnostics" Version="1.1.1" /> 
<PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="1.1.1" /> 
<PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="1.1.1" /> 
<PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.2" /> 
<PackageReference Include="Microsoft.AspNetCore.Server.IISIntegration" Version="1.1.1" /> 
<PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="1.1.1" /> 
<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="1.1.1" /> 
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="1.1.1" /> 
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer.Design" Version="1.1.1" /> 
<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="1.1.0" /> 
<PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="1.1.1" /> 
<PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="1.1.1" /> 
<PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="1.1.1" /> 
<PackageReference Include="Microsoft.Extensions.Logging" Version="1.1.1" /> 
<PackageReference Include="Microsoft.Extensions.Logging.Console" Version="1.1.1" /> 
<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="1.1.1" /> 
<PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="1.1.1" /> 
<PackageReference Include="Microsoft.VisualStudio.Web.BrowserLink" Version="1.1.0" /> 
<PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="1.1.0" /> 
After:
<PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />

Before:
<DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="1.0.0" />
<DotNetCliToolReference Include="Microsoft.Extensions.SecretManager.Tools" Version="1.0.0" />
<DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="1.0.0" />
 
After:
<DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="2.0.0" />
<DotNetCliToolReference Include="Microsoft.Extensions.SecretManager.Tools" Version="2.0.0" />
<DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="2.0.0" />

Step 4: Update in Program.cs Class Before: public static void Main(string[] args) { var host = new WebHostBuilder() .UseKestrel() .UseContentRoot(Directory.GetCurrentDirectory()) .UseIISIntegration() .UseStartup() .Build(); host.Run(); } After: public static void Main(string[] args) { BuildWebHost(args).Run(); } public static IWebHost BuildWebHost(string[] args) => WebHost.CreateDefaultBuilder(args) .UseStartup() .Build(); Step 5: Update in StartUp.cs

services.AddIdentityServer()
                    .AddDeveloperSigningCredential()
                    .AddInMemoryPersistedGrants()
                    .AddInMemoryIdentityResources(Config.GetIdentityResources())
                    .AddInMemoryApiResources(Config.GetApiResources())
                    .AddInMemoryClients(Config.GetClients())
                    .AddAspNetIdentity<ApplicationUser>();

        Before:
        app.UseIdentity();
        After:
        app.UseAuthentication();

Step 6:?Changes in Manage Login ViewModel

Before:
public IList<AuthenticationDescription> OtherLogins { get; set; }
 
After:
public IList<AuthenticationScheme> OtherLogins { get; set; }

Step 7: Changes in Manager Controller

Before:
var otherLogins = _signInManager
                  .GetExternalAuthenticationSchemes()
                  .Where(auth => userLogins
                                 .All(ul => auth.AuthenticationScheme != ul.LoginProvider))
                  .ToList();
 
After:
var otherLogins = (await _signInManager
                   .GetExternalAuthenticationSchemesAsync())
                  .Where(auth => userLogins
                                 .All(ul => auth.Name != ul.LoginProvider))
                  .ToList();

Step 8: Change sin Login.cshtml file Before: var loginProviders = SignInManager.GetExternalAuthenticationSchemes().ToList(); After: var loginProviders = (await SignInManager.GetExternalAuthenticationSchemesAsync()).ToList();

Before:
<button type="submit" class="btn btn-default" 
        name="provider" value="@provider.AuthenticationScheme" 
        title="Log in using your @provider.DisplayName account">
    @provider.AuthenticationScheme
</button>
 
After:
<button type="submit" class="btn btn-default" 
        name="provider" value="@provider.Name" 
        title="Log in using your @provider.DisplayName account">
    @provider.Name
</button>