Setting Base Path using ConfigurationBuilder

I'm trying to set the application base path for a .Net web app I'm building. I keep getting errors on Configuration builder. This is the error I get.

DNX,Version=v4.5.1 error CS1061: 'ConfigurationBuilder' does not contain a definition for 'SetBasePath' and no extension method 'SetBasePath' accepting a first argument of type 'ConfigurationBuilder' could be found (are you missing a using directive or an assembly reference?)

I'm assuming I'll get the same error for my .AddJsonFile() and .AddEnvironmentVariables(). Did I do something wrong? Did I not add the right dependency to my project.json? I've enclosed my startup.cs and my project.json.

project.json

{
"version": "1.0.0-*",
"compilationOptions": {
"emitEntryPoint": true
},
"tooling": {
"defaultNamespace": "TripPlanner"
},

"dependencies": {
  "Microsoft.AspNet.StaticFiles":  "1.0.0-rc1-final",
  "Microsoft.AspNet.Server.Kestrel": "1.0.0-rc1-final",
  "Microsoft.AspNet.Mvc": "6.0.0-rc1-final",
  "Microsoft.AspNet.Mvc.TagHelpers": "6.0.0-rc1-final",
  "Microsoft.Framework.Configuration": "1.0.0-beta8",
  "Microsoft.Framework.DependencyInjection": "1.0.0-beta8"
  //"Microsoft.Extensions.PlatformAbstractions": "1.0.0-beta8"
},

"commands": {
  "web": "Microsoft.AspNet.Server.Kestrel"
},

"frameworks": {
  "dnx451": { },
  "dnxcore50": { }
},

"exclude": [
  "wwwroot",
  "node_modules"
],
"publishExclude": [
  "**.user",
  "**.vspscc"
 ]
}

startup.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNet.Builder;
using Microsoft.AspNet.Hosting;
using Microsoft.AspNet.Http;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.PlatformAbstractions;
using Microsoft.Framework.Configuration;
using Microsoft.Framework.DependencyInjection;
using TripPlanner.Services;



namespace TripPlanner
{
  public class Startup
  {
    public static IConfigurationRoot Configuration;
    
    public Startup(IApplicationEnvironment appEnv){
        var builder = new ConfigurationBuilder()
            .SetBasePath(appEnv.ApplicationBasePath)
            .AddJsonFile("config.json")
            .AddEnvironmentVariables();
        
        Configuration = builder.Build();
    }
    
    // This method gets called by the runtime. Use this method to add services to the container.
    // For more information on how to configure your application, visit http://go.microsoft.com/fwlink/?LinkID=398940
    public void ConfigureServices(Microsoft.Extensions.DependencyInjection.IServiceCollection services)
    {
        services.AddMvc();
        #if DEBUG
        services.AddScoped<IMailService, DebugMailService> ();
        #else
        services.AddScoped<IMailService, RealMailService> ();
        #endif
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app)
    {
       //app.UseDefaultFiles();
       app.UseStaticFiles();
       app.UseMvc(config =>
       {
           config.MapRoute(
               name: "Default",
               template: "{controller}/{action}/{id?}",
               defaults: new { controller  = "App", action = "Index"}
           );
       });
       
    }

    // Entry point for the application.
    public static void Main(string[] args) => Microsoft.AspNet.Hosting.WebApplication.Run<Startup>(args);
  }
}

The error is in the public startup function right near the top of startup.cs.

I was able to solve the issue. If you have not yet solved it, try the following in the project.json. Add the following:

"Microsoft.Extensions.Configuration.FileExtensions": "1.0.0-*",
"Microsoft.Extensions.Configuration.Json": "1.0.0-rc2-final"

and it should work

Not sure if anyone still runs into this issue but I was able to address this in a dotnetcore console project (netcoreapp2.0) via:

dotnet add package Microsoft.Extensions.Configuration.Json

Try adding the following in your .csproj file:

<ItemGroup>
    <PackageReference Include="Microsoft.Extensions.Configuration" Version="2.2.0" />
    <PackageReference Include="Microsoft.Extensions.Configuration.FileExtensions" Version="2.2.0" />
    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="2.2.0" />
</ItemGroup>

Just piling on with one more possible issue...

I had to add this:

<PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="3.0.0" />

in order for this to compile:

var builder = new ConfigurationBuilder()
  .SetBasePath(Directory.GetCurrentDirectory())
  ...

Edit: I wrote this answer several months ago, but I'm pretty sure it was for a console app.

If you`re running a .NET Core 1.x or .NET Standard 1.x, you should run this command:

dotnet add package Microsoft.Extensions.Configuration.Json -v 1.1.1

If your project is inside another folder:

dotnet add .\src\MyProject package Microsoft.Extensions.Configuration.Json -v 1.1.1

...where MyProject is the name of the .csproj file.

Something else to consider:

using Microsoft.Extensions.Configuration;

Without that "using" statement, it doesn't find the extension method in Microsoft.Extensions.Configuration.FileExtensions.

The trouble cropped up for me because we were also:

using System.Configuration;

And there was a name clash with "ConfigurationBuilder". Add the

using Microsoft.Extensions.Configuration;

line... remove the

using System.Configuration;

line, then fully qualify anything under System.Configuration.

Try adding the following to your project.json dependencies:

"Microsoft.Extensions.Configuration": "1.0.0-*",
"Microsoft.Extensions.Configuration.Abstractions": "1.0.0-*",

Add the following to your project.json:

"Microsoft.Extensions.Configuration.FileExtensions": "1.0.0-*"

Try adding the following to your project.json dependencies: "Microsoft.Extensions.Configuration.CommandLine": "1.1.1",

Or in project.csproj:
<PackageReference Include="Microsoft.Extensions.Configuration.CommandLine" Version="1.1.1" />

This worked for me.

Additionally do not forget to set "Copy to Output Directory" property to "Copy always" of Json file from Properties window.