运行添加迁移时无法加载程序集Microsoft.EntityFrameworkCore.Design

问题描述

我用以下.csproj创建了一个类库项目：

I have created a Class Library project with the following .csproj:

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

  <PropertyGroup>
    <TargetFramework>netcoreapp1.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" 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" />
  </ItemGroup>

</Project>

运行命令时：

Add-Migration -Name Test -Context TestContext

我正在出现以下错误：

System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.EntityFrameworkCore.Design, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.
File name: 'Microsoft.EntityFrameworkCore.Design, Culture=neutral, PublicKeyToken=null'
   at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks, IntPtr ptrLoadContextBinder)
   at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks, IntPtr ptrLoadContextBinder)
   at System.Reflection.Assembly.Load(AssemblyName assemblyRef)
   at Microsoft.EntityFrameworkCore.Tools.ReflectionOperationExecutor..ctor(String assembly, String startupAssembly, String projectDir, String contentRootPath, String dataDirectory, String rootNamespace, String environment)
   at Microsoft.EntityFrameworkCore.Tools.Commands.ProjectCommandBase.CreateExecutor()
   at Microsoft.EntityFrameworkCore.Tools.Commands.MigrationsAddCommand.Execute()
   at Microsoft.DotNet.Cli.CommandLine.CommandLineApplication.Execute(String[] args)
   at Microsoft.EntityFrameworkCore.Tools.Program.Main(String[] args)
Could not load file or assembly 'Microsoft.EntityFrameworkCore.Design, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.

但是已经安装了Microsoft.EntityFrameworkCore.Design。

However Microsoft.EntityFrameworkCore.Design is already installed.

我正在使用Visual Studio Community 2017（VisualStudio / 15.0.0 + 26228.9）

I am using Visual Studio Community 2017 (VisualStudio/15.0.0+26228.9)

我缺少什么？

推荐答案

在添加Microsoft.EntityFrameworkCore.Tools.DotNet并将dotnet工具的版本更改为1.0.0-msbuild2-final之后，它起作用了，现在我的.csproj是：

It worked after adding Microsoft.EntityFrameworkCore.Tools.DotNet and changing the versions of dotnet tools to 1.0.0-msbuild2-final, now my .csproj is:

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

  <PropertyGroup>
    <TargetFramework>netcoreapp1.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" 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="1.0.0-msbuild2-final" />
    <DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="1.0.0-msbuild2-final" />
  </ItemGroup>

</Project>

这篇关于运行添加迁移时无法加载程序集Microsoft.EntityFrameworkCore.Design的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！