ASP.NET Core 2.2 to 3.0 migration

[Rick-Anderson]

[natemcmaster]

We're getting close to 3.0 Preview 1. Here is some information that I shared with our testers which I believe will also be relevant for customers.

The following changes need to be made to project files to upgrade from ASP.NET Core 2.x to 3.0.

• Update <TargetFramework> to netcoreapp3.0

• Remove the <PackageReference> to Microsoft.AspNetCore.All and Microsoft.AspNetCore.App.

  • Preview 1 Known Issue - workaround for Represent FrameworkReferences in NuGet - pack & restore support NuGet/Home#7342 - projects which do not start with <Project Sdk="Microsoft.NET.Sdk.Web"> will get compiler or runtime errors due to missing Microsoft.AspNetCore.* assemblies. This is most often the case for test projects and class libraries. The workaround is to add the following to the .csproj file.

   	<ItemGroup>
   	   <FrameworkReference Include="Microsoft.AspNetCore.App" />
   	</ItemGroup>

• Update the Version on remaining <PackageReference>'s to Microsoft.AspNetCore.* packages to 3.0.0-preview-18579-0053 (or whatever the Preview 1 build number ends up being)

  • If there is no such version of the package, this may be one of the packages which has been deprecated in 3.0. Many of these are part of Microsoft.AspNetCore.App and do not need to be referenced individually anymore.
    TODO: document a complete list of packages we no longer produce. Rough draft here: Stop producing packages for shared framework assemblies in 3.0 aspnetcore#3756

• Some APIs were removed from Microsoft.AspNetCore.App between 2.x and 3.0. You may need to add <PackageReference> items if you are using API from packages listed in Assemblies being removed from Microsoft.AspNetCore.App 3.0 aspnetcore#3755

  • Notable mentions: Entity Framework Core and System.Data.SqlClient are no longer part of Microsoft.AspNetCore.App.
  • Preview 1 Known Issue - the assemblies shipping in Microsoft.AspNetCore.App has not been finalized yet and will change before 3.0 RTM. We intend to remove a few more assemblies, most notably Newtonsoft.Json.