using System;

using System.Collections.Generic;

using System.Linq;

using Newtonsoft.Json;

​

public class Application

{

    [JsonProperty("roles")]

    public IEnumerable<string> Roles { get; set; }

}

​

public class User

{

    [JsonProperty("user_info")]

    public IDictionary<string, Application> UserInfo { get; set; }

}

public class Program

{

    public static void Main()

    {

        var json = @"{

                ""user_info"": {

                    ""myapp1"": {

                      ""roles"": [

                      ""requestor""

                      ]

                    },

                    ""myapp2"": {

                      ""roles"": [

                        ""requests-edit"",

                        ""requests-view""

                      ]

                    },

                    ""account"": {

                      ""roles"": [

                        ""manage-account"",

                        ""manage-account-links"",

                        ""view-profile""

                      ]

                    }

                  }

                }";

        var deserializedJson = JsonConvert.DeserializeObject<User>(json);

        Console.WriteLine("[ " + string.Join(", ", GetUserApplicationRoles("myapp1", deserializedJson)) + " ]");

        Console.WriteLine("[ " + string.Join(", ", GetUserApplicationRoles("myapp2", deserializedJson)) + " ]");

        Console.WriteLine("[ " + string.Join(", ", GetUserApplicationRoles("account", deserializedJson)) + " ]");

    }

    private static IEnumerable<string> GetUserApplicationRoles(string applicationName, User data) => 

        data.UserInfo

            .TryGetValue(applicationName, out var value) ?

                value.Roles : 

                Enumerable.Empty<string>();

}