通过 Graph SDK 获取用户联系人

Question

I try to read all users contacts by using graph sdk and c# but in the user at the response always the array of contacts is null even though the user has contacts

I was requesting all user's contacts from exchange online with graph sdk and c#, but

var graphResult = graphClient.Users.Request().GetAsync().Result;
            Console.WriteLine(graphResult[0].Contacts[0]); 

returns NullReferenceException .

I granted following privileges:

the following token is set in azure

here you can see my tenant id and so on

Main Class

using Microsoft.Graph;
using Azure.Identity;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Identity.Client;
using System.Data.SqlClient;

namespace ExchangeTestAppKonsole
{
    internal class Program
    {
        static void Main(string[] args)
        {

            getContacts();

            Console.ReadLine();
        }

        public static void getContacts()
        {
            var clientId = "de196208-b4d7-468f-8fa4-7328551566b9";
            var clientSecret = "~uG8Q~~vrTGuaIPfzeIR9GUUpSK5aaG.KZTYGcnD";
            var redirectUri = "https://global.consent.azure-apim.net/redirect";
            var authority = "https://login.microsoftonline.com/0be300e6-91fd-4638-bcd1-40d742ef6ece/v2.0";
            var cca = ConfidentialClientApplicationBuilder.Create(clientId)
                                                          .WithAuthority(authority)
                                                          .WithRedirectUri(redirectUri)
                                                          .WithClientSecret(clientSecret)
                                                          .Build();


            // use the default permissions assigned from within the Azure AD app registration portal
            List<string> scopes = new List<string>();
            scopes.Add("https://graph.microsoft.com/.default");

            var authenticationProvider = new MsalAuthenticationProvider(cca, scopes.ToArray());
            GraphServiceClient graphClient = new GraphServiceClient(authenticationProvider);

            var graphResult = graphClient.Users.Request().GetAsync().Result;
            Console.WriteLine(graphResult[0].Contacts[0]);
        }
    }
}

Authentication Provider

using Microsoft.Graph;
using Microsoft.Identity.Client;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http.Headers;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;

namespace ExchangeTestAppKonsole
{
    internal class MsalAuthenticationProvider : IAuthenticationProvider
    {
        private IConfidentialClientApplication _clientApplication;
        private string[] _scopes;

        public MsalAuthenticationProvider(IConfidentialClientApplication clientApplication, string[] scopes)
        {
            _clientApplication = clientApplication;
            _scopes = scopes;
        }

        public async Task AuthenticateRequestAsync(HttpRequestMessage request)
        {
            var token = await GetTokenAsync();
            request.Headers.Authorization = new AuthenticationHeaderValue("bearer", token);
        }

        public async Task<string> GetTokenAsync()
        {
            AuthenticationResult authResult = null;
            authResult = await _clientApplication.AcquireTokenForClient(_scopes).ExecuteAsync();
            return authResult.AccessToken;
        }
    }
}

I also requested the contacts of the first user by logging in with this user into graphExplorer and requested the /me/contacts endpoint it shows 3 contacts

it seems to be a premissions thing but i've no idea what exactly the problem is.

Answer 1

Contacts is a relationship on User resource type.

If you want to include some relationship in the response, you need to specify the relationship in Expand .

Not all relationships and resources support the expand. According to the documentation there is no mention that contacts supports expand, so probably this code won't work.

var graphResult = graphClient.Users
                   .Request()
                   .Expand("contacts")
                   .GetAsync().Result();
        Console.WriteLine(graphResult[0].Contacts[0]);

In that case you need to make a separate call for each user to get contacts.

var contacts = await graphClient.Users["{user_id}"].Contacts
    .Request()
    .GetAsync();

Users relationships