Json 您的项目没有引用.NETFramework,Version=v4.5框架.

我用的是VS 2015.

您的项目没有引用".NETFramework，版本=4.5"

I am getting this error on my Data Access and Business Logic layers, shortly after adding to my MVC Layer. Things were building fine until then, but I don't know what triggered this error. Here is my project.json:

{
  "version": "1.0.0-*",
  "description": "foo bar Class Library",
  "authors": [ "foo bar" ],
  "tags": [ "" ],
  "projectUrl": "",
  "licenseUrl": "",

  "frameworks": {
    "net451": { },
    "dotnet5.4": {
      "dependencies": {
        "Microsoft.CSharp": "4.0.1-beta-23516",
        "System.Collections": "4.0.11-beta-23516",
        "System.Linq": "4.0.1-beta-23516",
        "System.Runtime": "4.0.21-beta-23516",
        "System.Threading": "4.0.11-beta-23516"
      }
    }
  }
}

以下是我try 过的:

1. Replacing "dotnet5.4" with "net451" (and deleting it) as found in this answer.

Result is the same error.

2. 将"dotnet5.4"改为"net45"，留下"net451".这会导致新的错误:

你的项目.json没有运行时部分.你应该加上

我试着按照这个错误提示的那样做，并添加了

"runtimes": {
    "win":  {}
  },

This got me this error, which I can't seem to move past:

你的项目.json没有将"win"列为目标运行时.你应该

I've already added "win", and this is beginning to feel like a red herring. What am I doing altering the project.json directly, isn't NuGet handling this?