This repository is for AspNetCore Issue #19481 (Reference IEndpointRouteBuilder in a class library (ASP.NET Core 3.1)).
As reported in AspNetCore Issue #16638 (Cannot find the AspNetCore Nuget packages for 3.0 (specifically routing)),
it seems like the only way to reference IEndpointRouteBuilder from ASP.NET Core 3.1 (SDK 3.1.102) is to setup a project with an
SDK of Microsoft.NET.SDK.Web and a TargetFramework of netcoreapp3.1 (example .csproj):
<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>netcoreapp3.1</TargetFramework>
</PropertyGroup>
</Project>
However, if you want to create a shared library (nuget package) which was configured in that way, then the compiler would produce this error:
1>Done building project "IEndpointRouteBuilderDemo-DoesntCompile.csproj" -- FAILED.
1>
1>Build FAILED.
1>
1>CSC : error CS5001: Program does not contain a static 'Main' method suitable for an entry point
The error seems pretty logical, seeing that it's trying to target a netcorapp, which is assumed to be
an executable application.
But the original question in AspNetCore Issue #16638 (Cannot find the AspNetCore Nuget packages for 3.0 (specifically routing))
hasn't been solved. How can you create a class library that references IEndpointRouteBuilder successfully?
One thing that can be done right now, is to include a DummyMain.cs file, which gets around the error
message. But, that really doesn't feel like the intent of the original AspNetCore team.
namespace IEndpointRouteBuilderDemo
{
public class DummyMain
{
public static void Main(string[] args)
{
}
}
}
So, how can IEndpointRouteBuilder be referenecd in a class library without needing a DummyMain.cs?
The .csproj file should reference SDK Microsoft.NET.SDK (instead of Microsoft.NET.SDK.Web) and Shared Framework Microsoft.AspNetCore.App.
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFramework>netcoreapp3.1</TargetFramework>
</PropertyGroup>
<ItemGroup>
<FrameworkReference Include="Microsoft.AspNetCore.App" />
</ItemGroup>
</Project>