Microsoft Graph Training Module - Using Microsoft Graph .NET SDK to interact with Outlook Calendar

In this demo you will create a .NET console application from scratch using .NET Framework 4.7.2, the Microsoft Graph SDK, and the Microsoft Authentication Library (MSAL).

Register the application

1. Navigate to the the Azure portal - App registrations to register your app. Login using a personal account (aka: Microsoft Account) or Work or School Account.

2. Select New registration. On the Register an application page, set the values as follows.

• Set Name to ConsoleDemoCalendar.
• Set Supported account types to Accounts in any organizational directory and personal Microsoft accounts.
• Leave Redirect URI empty.
• Choose Register.

3. On the ConsoleDemoCalendar page, copy the values of both the Application (client) ID and the Directory (tenant) ID. Save these two values, since you will need them later.

4. Select the Add a Redirect URI link. On the Redirect URIs page, locate the Suggested Redirect URIs for public clients (mobile, desktop) section. Select the URI that begins with msal and the urn:ietf:wg:oauth:2.0:oob URI.

5. Open the sample solution in Visual Studio and then open the App.config file. Change the clientId string to the Application (client) ID value.

Create the project in Visual Studio 2017

1. In Visual Studio 2017, create a new Console Application project targeting .NET Framework 4.7.2.

   

2. Select Tools > NuGet Package Manager > Package Manager Console. In the console window, run the following commands:

   Install-Package "Microsoft.Graph"
   Install-Package "Microsoft.Identity.Client" -Version 2.7.1
   Install-Package "System.Configuration.ConfigurationManager"

3. Edit the app.config file, and immediately before the /configuration element, add the following element replacing the value with the Application ID provided by the Application Registration Portal:

   <appSettings>
       <add key="clientId" value="YOUR APPLICATION ID"/>
   </appSettings>

   Note: Make sure to replace the value with the Application ID value provided from the Application Registration Portal.

Add AuthenticationHelper.cs

1. Add a class to the project named AuthenticationHelper.cs. This class will be responsible for authenticating using the Microsoft Authentication Library (MSAL), which is the Microsoft.Identity.Client package that we installed.

2. Replace the using statement at the top of the file.

   using Microsoft.Graph;
   using Microsoft.Identity.Client;
   using System;
   using System.Configuration;
   using System.Diagnostics;
   using System.Linq;
   using System.Net.Http.Headers;
   using System.Threading.Tasks;

3. Replace the class declaration with the following:

   public class AuthenticationHelper
   {
       // The Client ID is used by the application to uniquely identify itself to the v2.0 authentication endpoint.
       static string clientId = ConfigurationManager.AppSettings["clientId"].ToString();
       public static string[] Scopes = { "Calendars.Read","Calendars.ReadWrite" };
   
       public static PublicClientApplication IdentityClientApp = new PublicClientApplication(clientId);
   
       private static GraphServiceClient graphClient = null;       
   
       // Get an access token for the given context and resourceId. An attempt is first made to
       // acquire the token silently. If that fails, then we try to acquire the token by prompting the user.
       public static GraphServiceClient GetAuthenticatedClient()
       {
           if (graphClient == null)
           {
               // Create Microsoft Graph client.
               try
               {
                   graphClient = new GraphServiceClient(
                       "https://graph.microsoft.com/v1.0",
                       new DelegateAuthenticationProvider(
                           async (requestMessage) =>
                           {
                               var token = await GetTokenForUserAsync();
                               requestMessage.Headers.Authorization = new AuthenticationHeaderValue("bearer", token);
                           }));
                   return graphClient;
               }
   
               catch (Exception ex)
               {
                   Debug.WriteLine("Could not create a graph client: " + ex.Message);
               }
           }
   
           return graphClient;
       }
   
       /// <summary>
       /// Get Token for User.
       /// </summary>
       /// <returns>Token for user.</returns>
       public static async Task<string> GetTokenForUserAsync()
       {
           AuthenticationResult authResult = null;
           try
           {
               IEnumerable<IAccount> accounts = await IdentityClientApp.GetAccountsAsync();
               IAccount firstAccount = accounts.FirstOrDefault();
   
               authResult = await IdentityClientApp.AcquireTokenSilentAsync(Scopes, firstAccount);                
               return authResult.AccessToken;
           }
           catch (MsalUiRequiredException ex)
           {
               // A MsalUiRequiredException happened on AcquireTokenSilentAsync.
               //This indicates you need to call AcquireTokenAsync to acquire a token
   
               authResult = await IdentityClientApp.AcquireTokenAsync(Scopes);
   
               return authResult.AccessToken;
           }
       }
   
       /// <summary>
       /// Signs the user out of the service.
       /// </summary>
       public static void SignOut()
       {
           foreach (var user in IdentityClientApp.GetAccountsAsync().Result)
           {
               IdentityClientApp.RemoveAsync(user);
           }
           graphClient = null;
       }
   }

Disclaimer

THIS CODE IS PROVIDED AS IS WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING ANY IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR NON-INFRINGEMENT.