visual-studio-2015 - 无法识别术语 "Add-Migration"

Question

我正在使用这个MSDN Tutorial在 VS2015 中运行命令 PM> Add-Migration MyFirstMigration -context BloggingContext 昨天成功运行，但今天它给出了以下错误，其他用户也指出了 here 。我什至从解决方案资源管理器中删除了 Migrations 文件夹，并从 Win 8.1 上的 SQL Express 2014 中删除了相应的数据库，但出现了同样的错误。即使我运行 Add-Migration MyFirstMigration 我也会得到同样的错误:

Add-Migration : The term 'Add-Migration' is not recognized as the name of a cmdlet, function, script file, or operable program. 
Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At line:1 char:1
+ Add-Migration MyFirstMigration -context BloggingContext
+ ~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (Add-Migration:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

注意:我使用的是最新版本的 ASP.NET Core 1.0 和 VS2015 - 2016 年 6 月 27 日发布的更新 3。

更新

使用命令窗口时，以下命令可以在 Windows 资源管理器中的项目目录中正常工作:

> dotnet ef migrations add MyFirstMigration --context BloggingContext
> dotnet ef database update --context BloggingContext

更新2a

以下是project.json文件:

{
  "userSecretsId": "aspnet-ASPCore_RTM_CodeFirst_test-bef835d9-9831-41a8-bc3a-cd2f1477a880",

  "dependencies": {
    "Microsoft.NETCore.App": {
      "version": "1.0.0",
      "type": "platform"
    },
    "Microsoft.AspNetCore.Authentication.Cookies": "1.0.0",
    "Microsoft.AspNetCore.Diagnostics": "1.0.0",
    "Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore": "1.0.0",
    "Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.0.0",
    "Microsoft.AspNetCore.Mvc": "1.0.0",
    "Microsoft.AspNetCore.Razor.Tools": {
      "version": "1.0.0-preview2-final",
      "type": "build"
    },
    "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0",
    "Microsoft.AspNetCore.Server.Kestrel": "1.0.0",
    "Microsoft.AspNetCore.StaticFiles": "1.0.0",
    "Microsoft.EntityFrameworkCore.SqlServer": "1.0.0",
    "Microsoft.EntityFrameworkCore.SqlServer.Design": {
      "version": "1.0.0",
      "type": "build"
    },
    "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final",
    "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0",
    "Microsoft.Extensions.Configuration.Json": "1.0.0",
    "Microsoft.Extensions.Configuration.UserSecrets": "1.0.0",
    "Microsoft.Extensions.Logging": "1.0.0",
    "Microsoft.Extensions.Logging.Console": "1.0.0",
    "Microsoft.Extensions.Logging.Debug": "1.0.0",
    "Microsoft.Extensions.Options.ConfigurationExtensions": "1.0.0",
    "Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.0.0",
    "Microsoft.VisualStudio.Web.CodeGeneration.Tools": {
      "version": "1.0.0-preview2-final",
      "type": "build"
    },
    "Microsoft.VisualStudio.Web.CodeGenerators.Mvc": {
      "version": "1.0.0-preview2-final",
      "type": "build"
    }
  },

  "tools": {
    "BundlerMinifier.Core": "2.0.238",
    "Microsoft.AspNetCore.Razor.Tools": "1.0.0-preview2-final",
    "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final",
    "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final",
    "Microsoft.Extensions.SecretManager.Tools": "1.0.0-preview2-final",
    "Microsoft.VisualStudio.Web.CodeGeneration.Tools": {
      "version": "1.0.0-preview2-final",
      "imports": [
        "portable-net45+win8"
      ]
    }
  },

  "frameworks": {
    "netcoreapp1.0": {
      "imports": [
        "dotnet5.6",
        "portable-net45+win8"
      ]
    }
  },

  "buildOptions": {
    "emitEntryPoint": true,
    "preserveCompilationContext": true
  },

  "runtimeOptions": {
    "configProperties": {
      "System.GC.Server": true
    }
  },

  "publishOptions": {
    "include": [
      "wwwroot",
      "Views",
      "Areas/**/Views",
      "appsettings.json",
      "web.config"
    ]
  },

  "scripts": {
    "prepublish": [ "bower install", "dotnet bundle" ],
    "postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
  }
}

Answer 1

只需从 nuget 安装 Microsoft.EntityFrameworkCore.Tools 包:

Install-Package Microsoft.EntityFrameworkCore.Tools -Version 7.0.7

您还可以使用此链接安装最新版本: NuGet package link

.NET CLI 命令:

dotnet add package Microsoft.EntityFrameworkCore.Tools

如果问题仍然存在，请尝试重新启动 Visual Studio。