Getting shared calendar events with Microsoft.Graph - asp.net-core

Question

I'm trying to recreate the following example: https://learn.microsoft.com/en-us/graph/outlook-get-shared-events-calendars
I'm using ASP.NET Core 3.1, Azure AD, and the Microsoft.Graph API. I was able to retrieve events from my personal calendar, as well as the name, ID, owner etc. from the shared calendars. The events from the shared calendars, however, refuse to show. I couldn't find any examples, Microsoft's or otherwise.
Here's the code I'm using:
[Authorize]
[AuthorizeForScopes(ScopeKeySection = "MicrosoftGraph:Scopes")]
public class HomeController : Controller
{
private readonly ILogger<HomeController> _logger;
private readonly GraphServiceClient graphServiceClient;
private readonly MicrosoftIdentityConsentAndConditionalAccessHandler _consentHandler;
private string[] _graphScopes;
public HomeController(ILogger<HomeController> logger, GraphServiceClient gsc,
MicrosoftIdentityConsentAndConditionalAccessHandler consentHandler
)
{
_logger = logger;
graphServiceClient = gsc;
this._consentHandler = consentHandler;
_graphScopes = Startup.ConfigurationInstance.GetSection("MicrosoftGraph")["Scopes"].Split(" ");
}
[AuthorizeForScopes(ScopeKeySection = "MicrosoftGraph:Scopes")]
public IActionResult Index()
{
User currentUser = null;
try
{
currentUser = graphServiceClient.Me.Request().GetAsync().Result;
}
// Catch CAE exception from Graph SDK
catch (ServiceException svcex) when (svcex.Message.Contains("Continuous access evaluation resulted in claims challenge"))
{
try
{
Console.WriteLine($"{svcex}");
string claimChallenge = WwwAuthenticateParameters.GetClaimChallengeFromResponseHeaders(svcex.ResponseHeaders);
_consentHandler.ChallengeUser(_graphScopes, claimChallenge);
return new EmptyResult();
}
catch (Exception ex2)
{
_consentHandler.HandleException(ex2);
}
}
var viewOptions = new List<QueryOption>
{
new QueryOption("startDateTime", DateTime.Today.ToString("o")),
new QueryOption("endDateTime", DateTime.Today.AddDays(20).ToString("o"))
};
var sha = graphServiceClient.Me.Calendars
.Request()
.Select(e => e.Id)
.GetAsync().Result.ToList();
var x = new List<Event>();
foreach(var row in sha)
{
var id = row.Id;
var data = graphServiceClient.Me.Calendars[id].Request(viewOptions)
.Select(e => e.Events).GetAsync().Result;
ICalendarEventsCollectionPage d1 = data != null? data.Events: null;
if (d1 != null)
{
x.AddRange(d1.ToList());
}
}
}
}
The above retrieves null events.
I tried to access the calendar directly from another user, as per another one of Microsoft's examples:
var x = graphServiceClient.Users["<email>"]
.CalendarView
.Request(viewOptions)
.Select(e => new
{
e.Subject,
e.Organizer,
e.Start,
e.End
}).GetAsync().Result;
The only thing I get from this code is 'access denied'.
My appsettings.json with the scopes set in the Azure AD tenant:
"AzureAd": {
"Instance": "https://login.microsoftonline.com/",
"Domain": "<domain>",
"TenantId": "<id>",
"ClientId": "<id>",
"CallbackPath": "/signin-oidc",
"SignedOutCallbackPath": "/signout-callback-oidc",
"ClientSecret": "<secret>"
},
"AllowedHosts": "*",
"MicrosoftGraph": {
"Scopes": "User.Read MailboxSettings.ReadWrite Calendars.ReadWrite.Shared",
"BaseUrl": "https://graph.microsoft.com/v1.0"
}
Any help with this would be greatly appreciated.

Answer 1

Your code and configuration don't seem to be the problem. Please check whether the Permissions to allow access is enabled in Outlook's calendar.
If the problem persists, here is a detailed documentation to guide you through the configuration step by step. You can refer to this documentation to see if some steps are missing.
Hop this can help you.