c# - 为什么 add-migration 命令没有创建迁移？不识别包裹

Question

安装以下软件包后:

"Microsoft.EntityFrameworkCore.SqlServer": "1.1.0", "Microsoft.EntityFrameworkCore.Tools": "1.1.0-preview4-final" (-Pre)

运行 add-migration "InitialCreate" 命令时，出现以下错误:

无法执行此命令，因为未安装 Microsoft.EntityFrameworkCore.Design。安装与安装的 Microsoft.EntityFrameworkCore 版本相匹配的包版本，然后重试。 不过，如果您查看下面的 .json 文件，您会发现这些包是匹配的，所以这个错误信息与我矛盾。

这是我的 project.json 文件:

{
  "runtimes": {
    "win10-x64": {}
  },

  "dependencies": {
    "Microsoft.AspNetCore.Diagnostics": "1.1.0",
    "Microsoft.AspNetCore.Mvc": "1.1.0",
    "Microsoft.AspNetCore.Server.IISIntegration": "1.1.0",
    "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final",
    "Microsoft.AspNetCore.Server.Kestrel": "1.1.0",
    "Microsoft.AspNetCore.StaticFiles": "1.1.0",
    "Microsoft.EntityFrameworkCore": "1.1.0",
    "Microsoft.EntityFrameworkCore.Design": "1.1.0",
    "Microsoft.EntityFrameworkCore.SqlServer": "1.1.0",
    "Microsoft.EntityFrameworkCore.Tools": "1.1.0-preview4-final",
    "Microsoft.Extensions.Configuration.FileExtensions": "1.1.0",
    "Microsoft.Extensions.Configuration.Json": "1.1.0",
    "Microsoft.Extensions.Logging.Console": "1.1.0",
    "Microsoft.NETCore.App": "1.1.0"
  },

  "tools": {
    "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final",
    "Microsoft.EntityFrameworkCore.Tools": "1.1.0-preview4-final"
  },

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

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

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

  "publishOptions": {
    "include": [
      "wwwroot",
      "web.config"
    ]
  },

  "scripts": {
    "postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
  }
} 

Answer 1

您需要更改您的 project.json，如下所示。

注意:需要包含"type": "platform"

{
  "dependencies": {
    "Microsoft.NETCore.App": {
      "version": "1.0.1",
      "type": "platform"
    }
  }
}

您可以在此处阅读有关此问题的更多信息:GitHub