Why does Visual Studio tell me that the AddJsonFile() method is not defined?

Question

I'm developing an ASP.NET 5 WebAPI project using VS Ultimate 2015 Preview.

I'm trying to configure the app in this way:

using Microsoft.Framework.ConfigurationModel;

public IConfiguration Configuration { get; private set; }

public Startup()
{
    Configuration = new Configuration()
        .AddJsonFile("config.json")
        .AddEnvironmentVariables();
}

Line 8 gives me an error:

'Configuration' does not contain a definition for 'AddJsonFile'...

What is wrong?

Answer 1

You need to include the Microsoft.Extensions.Configuration.Json NuGet package if you want to call the .AddJsonFile() method.

See: https://github.com/aspnet/Configuration/tree/dev/src/Microsoft.Framework.ConfigurationModel.Json

For further reading, here's a nice tutorial: ASP.NET vNext Moving Parts: IConfiguration.