GetActiveDirectoryClientmethod from Property Inspection Code Sample. Part of the AuthenticationHelper class found here: https://github.com/OfficeDev/Property-Inspection-Code-Sample/blob/master/PropertyManagerMyApp/PropertyManagerMyApp/Utils/AuthenticationHelper.cs

gistfile1.txt

private async Task<ActiveDirectoryClient> GetActiveDirectoryClient()
        {
            Uri baseServiceUri = new Uri(AADAppSettings.AADGraphResourceId);
            var tenantId = ClaimsPrincipal.Current.FindFirst("http://schemas.microsoft.com/identity/claims/tenantid").Value;
            ActiveDirectoryClient activeDirectoryClient =
                new ActiveDirectoryClient(new Uri(baseServiceUri, tenantId),
                    async () => await AcquireTokenAsync());

            return activeDirectoryClient;
        }