我分两步对其进行了修复.

1.从程序包管理器控制台安装Razor工具.它现在是预发布的

Install-Package Microsoft.AspNetCore.Razor.Tools –Pre

2. 从市场上下载并安装 Razor Language Services . (您的Visual Studio实例应关闭)

重新启动Visual Studio之后，智能感知和着色应可用于标记助手.

I am having issues with .NET core and tag helpers. The color coding and the intellisense are not displaying or being registered when I type in asp-for. I've tried creating a new solution in a separate instance, verified that the intellisense works, and then copied the project.json into the project that doesn't have working intellisense/color coding, and it doesn't fix the issue.

Here is my project.json

{
  "dependencies": {
    "Microsoft.NETCore.App": {
      "version": "1.0.0",
      "type": "platform"
    },
    "Microsoft.AspNet.Tooling.Razor": "1.0.0-rc1-final",
    "Microsoft.AspNetCore.Diagnostics": "1.0.0",
    "Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.0.0",
    "Microsoft.AspNetCore.Mvc": "1.0.1",
    "Microsoft.AspNetCore.Mvc.TagHelpers": "1.0.1",
    "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0",
    "Microsoft.AspNetCore.Server.Kestrel": "1.0.1",
    "Microsoft.AspNetCore.StaticFiles": "1.0.0",
    "Microsoft.EntityFrameworkCore.SqlServer": "1.0.1",
    "Microsoft.Extensions.Configuration.FileExtensions": "1.1.0",
    "Microsoft.Extensions.Configuration.Json": "1.1.0",
    "Microsoft.Extensions.Logging.Console": "1.0.0",
    "Microsoft.Extensions.Logging.Debug": "1.0.0",
    "Microsoft.AspNetCore.Routing": "1.0.1",
    "Microsoft.AspNetCore.Razor.Tools": {
      "version": "1.0.0-preview2-final",
      "type": "build"
    },

    "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": {
    "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final",
    "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-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": {
    "prepublish": [ "bower install" ],
    "postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
  }
}

I've also made the reference/injection in the _ViewImports file for the mvc tag helpers. This is the view where I'm testing that it works.

And here is my project structure, just in case you can see something that I'm not seeing.

If it helps at all, here is the version of Visual Studio I am using.

I fixed it in two steps.

1.Install Razor tool from package manager console. It is pre-release for now

Install-Package Microsoft.AspNetCore.Razor.Tools –Pre

2. Download and install Razor Language Services from marketplace. (Your visual studio instance should be closed)

After restart visual studio, intellisense and coloring should be working for tag helpers.