Graph sample code for MSAL

Graphsamplecode.cs

using System;
using System.Net.Http;
using System.Threading.Tasks;
using Microsoft.Graph;
using Microsoft.Identity.Client;

namespace testconsole
{

    class GraphAuthenticator : IAuthenticationProvider
    {
        static string token;
        static DateTimeOffset Expiration;



        public async Task AuthenticateRequestAsync(HttpRequestMessage request)
        {

            string[] scopes = { "user.read", "mail.read", "mail.send" };
            var app = PublicClientApplicationBuilder.Create("cfc3a225-ac57-45c9-aacd-969551f4825f").Build();

            AuthenticationResult result = null;
            try
            {
                result = await app.AcquireTokenInteractive(scopes, null).ExecuteAsync();
                token = result.AccessToken;
            }
            catch (Exception)
            {
                if (string.IsNullOrEmpty(token) || Expiration <= DateTimeOffset.UtcNow.AddMinutes(5))
                {
                    result = await app.AcquireTokenInteractive(scopes, null).ExecuteAsync();
                    Expiration = result.ExpiresOn;
                    token = result.AccessToken;
                }
            }


            request.Headers.Add("Authorization", $"Bearer {token}");

        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            var client = new GraphServiceClient(new GraphAuthenticator());

            Console.WriteLine(client.Me.Request().GetAsync().Result.DisplayName);
        }
    }
}