asp.net core 1.1 项目升级至 asp.net core 2.0 preview 2

这两天把一个 asp.net core 1.1 的项目迁移到了 asp.net core 2.0 preview 2 ，在这篇随笔中记录一下。

如果项目在有 global.json 文件，需要删除或修改为 .net 2.0 preview 2 的 sdk 版本号。

对于类库项目的 .csproj，需要把 TagetFramework 改为 netstandard2.0 ，比如

<PropertyGroup>
  <TargetFramework>netstandard1.6</TargetFramework>
  <AssemblyName>CNBlogs.Identity.ServiceAgent</AssemblyName>
  <PackageId>CNBlogs.Identity.ServiceAgent</PackageId>
  <NetStandardImplicitPackageVersion>1.6.1</NetStandardImplicitPackageVersion>
  <GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
  <GenerateAssemblyCompanyAttribute>false</GenerateAssemblyCompanyAttribute>
  <GenerateAssemblyProductAttribute>false</GenerateAssemblyProductAttribute>
</PropertyGroup>

改为

<PropertyGroup>
  <TargetFramework>netstandard2.0</TargetFramework>
</PropertyGroup>

对于单元测试项目，TargetFramework 需要改为 netcoreapp2.0 ，比如

<PropertyGroup>
  <TargetFramework>netcoreapp1.1</TargetFramework>
  <AssemblyName>CNBlogs.Identity.UnitTests</AssemblyName>
  <PackageId>CNBlogs.Identity.UnitTests</PackageId>
  <GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>
  <RuntimeFrameworkVersion>1.1.1</RuntimeFrameworkVersion>
  <GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
  <GenerateAssemblyCompanyAttribute>false</GenerateAssemblyCompanyAttribute>
  <GenerateAssemblyProductAttribute>false</GenerateAssemblyProductAttribute>
</PropertyGroup>

改为

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

对于 web 项目，需要该动的地方很多。除了把 TargetFramework 改为 netcoreapp2.0 ，比如

<PropertyGroup>
  <TargetFramework>netcoreapp1.1</TargetFramework>
  <PreserveCompilationContext>true</PreserveCompilationContext>
  <AssemblyName>CNBlogs.Identity.Web</AssemblyName>
  <OutputType>Exe</OutputType>
  <PackageId>CNBlogs.Identity.Web</PackageId>
  <RuntimeIdentifiers>win10-x64;win8-x64;osx.10.12-x64;ubuntu.14.04-x64</RuntimeIdentifiers>
  <PackageTargetFallback>$(PackageTargetFallback);dnxcore50;portable-net45+win10</PackageTargetFallback>
  <RuntimeFrameworkVersion>1.1.1</RuntimeFrameworkVersion>
</PropertyGroup>

改为

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

还需要：

1）移除所有对 Microsoft.AspNetCore 的引用

<PackageReference Include="Microsoft.AspNetCore.Authentication" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.Authentication.Cookies" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.DataProtection.Extensions" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.DataProtection.Redis" Version="0.1.2" />
<PackageReference Include="Microsoft.AspNetCore.Diagnostics" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.Hosting" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.3" />
<PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.ViewCompilation" Version="1.1.1" />
<PackageReference Include="Microsoft.AspNetCore.Server.IISIntegration" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.Session" Version="1.1.2" />
<PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="1.1.2" />

添加 Microsoft.AspNetCore 的引用

<PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0-preview2-final" />

2）修改 Authentication 相关的代码

• CookieAuthenticationOptions 的命名空间改为 Microsoft.AspNetCore.Authentication.Cookies
• HttpContext.Authentication.SignInAsync() 改为 HttpContext.SignInAsync() ，需要安装 NuGet 包 Microsoft.AspNetCore.Authentication.Abstractions ，引用命名空间 Microsoft.AspNetCore.Authentication 。
• cookieAuthOptions.Value.AuthenticationScheme 改为 CookieAuthenticationDefaults.AuthenticationScheme

3） 针对 BundlerMinifier 的修改

在 asp.net core 2.0 preview 2 的 docker  容器中 build 项目，在执行 dotnet bundle 时出现下面的错误

It was not possible to find any compatible framework version
The specified framework ‘Microsoft.NETCore.App‘, version ‘1.1.0‘ was not found.
- Check application dependencies and target a framework version installed at:
    /
- Alternatively, install the framework version ‘1.1.0‘.

这是由于 nuget 包 BundlerMinifier.Core 不支持 .net core 2.0 。github 上签出 BundlerMinifier 的源码（已增加了对.net core 2.0的支持），自己打包。

升级时不仅要升级 PackageReference 中的 BundlerMinifier.Core ，还要升级 DotNetCliToolReference 中的 BundlerMinifier.Core 。

4）针对 DataProtection 的修改

Microsoft.AspNetCore.DataProtection.Redis 的 PersistKeysToRedis() 方法不起作用，需要改用临时解决方法：

services.Configure<KeyManagementOptions>(o =>
{
    o.XmlRepository = new RedisXmlRepository(() => redisConn.GetDatabase(), "DataProtection-Keys-Cnblogs");
});

详见 PersistKeysToRedis not working in .NET Core 2.0 Preview 2 with Redis 0.1.2

5）Startup 的修改

• 去除构造函数中下面的代码

  var builder = new ConfigurationBuilder()
      .SetBasePath(env.ContentRootPath)
      .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
      .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true);
  
  builder.AddEnvironmentVariables();
  Configuration = builder.Build();

• 去除 Configure 方法中下面的代码

  loggerFactory.AddSerilog();
  loggerFactory.AddConsole(Configuration.GetSection("Logging"));

• IConfigurationRoot 改为 IConfiguration

  public Startup(IConfiguration configuration)
  {
      Configuration = configuration;
  }
  
  public IConfiguration Configuration { get; set; }

6）Program 的修改

public class Program
{
    public static void Main(string[] args)
    {
        BuildWebHost(args).Run();
    }

    public static IWebHost BuildWebHost(string[] args)
    {
        return WebHost.CreateDefaultBuilder(args)
            .ConfigureLogging((context, logging) =>
            {
                logging.AddSerilog();
            })
            .UseStartup<Startup>()
            .Build();
    }
}

完成 web 项目升级后，升级所有 NuGet 包，删除所有 AssemblyInfo.cs 文件，整个升级就完成了。