Azure 函数 V3 无法加载文件或程序集 Microsoft.Extensions.DependencyInjection.Abstractions，Version=5.0.0.0 with EF core 5.0-rc1

Question

案件

我们正在使用 .netcore 3.1 创建 azure 函数 v3。使用EF 核心 5.0-rc1和依赖注入

1) 依赖注入

[assembly: FunctionsStartup(typeof(xxxxx.Startup))]
namespace xxxxx
{
    public class Startup : FunctionsStartup
    {
        public override void Configure(IFunctionsHostBuilder builder)
        {
            var services = builder.Services;
            var configBuilder = new ConfigurationBuilder()
                .SetBasePath(Environment.CurrentDirectory)
                .AddJsonFile("local.settings.json", true, reloadOnChange: true)
                .AddEnvironmentVariables() ;
            ConfigureServices(services);
            ConfigureAppSettings(services, configBuilder.Build());
            ConfigureLogging(services, configBuilder.Build());
        }
    }
}

2) EF 核心 5.0 rc-1

https://devblogs.microsoft.com/dotnet/annoucing-entity-framework-core-efcore-5-0-rc1/

错误

无法加载文件或程序集“Microsoft.Extensions.DependencyInjection.Abstractions，Version=5.0.0.0，Culture=neutral，PublicKeyToken=adb9793829ddae60”。该系统找不到指定的文件。

套餐

以下是引用的包

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <AzureFunctionsVersion>v3</AzureFunctionsVersion>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.Azure.Functions.Extensions" Version="1.1.0" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.ServiceBus" Version="4.1.0" />
    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="5.0.0-rc.1.20451.14" />
    <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="3.0.7" />
    <PackageReference Include="Serilog.Extensions.Logging" Version="3.0.1" />
    <PackageReference Include="Serilog.Sinks.Console" Version="3.1.1" />
  </ItemGroup>
  <ItemGroup>
    <None Update="host.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
    </None>
    <None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>Never</CopyToPublishDirectory>
    </None>
  </ItemGroup>
</Project>

故障排除

在startup.cs（依赖注入）中注释以下行即可解决问题

[assembly: FunctionsStartup(typeof(xxxxx.Startup))]

Answer 1

如果您使用 .NET Core 3.1 或更低版本。将Microsoft.Extensions.DependencyInjection和Microsoft.Extensions.DependencyInjection.Abstractions的 NuGet 包降级到 3.xx

Answer 2

这Microsoft.Azure.Functions.Extensions 取决于 .net 标准 2.0。

虽然Entity Framework Core 5.0 RC1 不会在 .Net 标准 2.0 平台上运行，但它需要.net 标准 2.1。所以它找不到Microsoft.Azure.Functions.Extensions.

更多细节，你可以参考这篇文章。