Program.cs

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT license.

// <ProgramSnippet>
using GraphAppOnlyTutorial;

Console.WriteLine(".NET Graph App-only Tutorial\n");

var settings = Settings.LoadSettings();

// Initialize Graph
InitializeGraph(settings);

int choice = -1;

while (choice != 0)
{
    Console.WriteLine("Please choose one of the following options:");
    Console.WriteLine("0. Exit");
    Console.WriteLine("1. Display access token");
    Console.WriteLine("2. List users");
    Console.WriteLine("3. Make a Graph call");

    try
    {
        choice = int.Parse(Console.ReadLine() ?? string.Empty);
    }
    catch (System.FormatException)
    {
        // Set to invalid value
        choice = -1;
    }

    switch (choice)
    {
        case 0:
            // Exit the program
            Console.WriteLine("Goodbye...");
            break;
        case 1:
            // Display access token
            await DisplayAccessTokenAsync();
            break;
        case 2:
            // List users
            await ListUsersAsync();
            break;
        case 3:
            // Run any Graph code
            await MakeGraphCallAsync();
            break;
        default:
            Console.WriteLine("Invalid choice! Please try again.");
            break;
    }
}
// </ProgramSnippet>

// <InitializeGraphSnippet>
void InitializeGraph(Settings settings)
{
    GraphHelper.InitializeGraphForAppOnlyAuth(settings);
}
// </InitializeGraphSnippet>

// <DisplayAccessTokenSnippet>
async Task DisplayAccessTokenAsync()
{
    try
    {
        var appOnlyToken = await GraphHelper.GetAppOnlyTokenAsync();
        Console.WriteLine($"App-only token: {appOnlyToken}");
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Error getting app-only access token: {ex.Message}");
    }
}
// </DisplayAccessTokenSnippet>

// <ListUsersSnippet>
async Task ListUsersAsync()
{
    try
    {
        var userPage = await GraphHelper.GetUsersAsync();

        if (userPage?.Value == null)
        {
            Console.WriteLine("No results returned.");
            return;
        }

        // Output each users's details
        foreach (var user in userPage.Value)
        {
            Console.WriteLine($"User: {user.DisplayName ?? "NO NAME"}");
            Console.WriteLine($"  ID: {user.Id}");
            Console.WriteLine($"  Email: {user.Mail ?? "NO EMAIL"}");
        }

        // If NextPageRequest is not null, there are more users
        // available on the server
        // Access the next page like:
        // var nextPageRequest = new UsersRequestBuilder(userPage.OdataNextLink, _appClient.RequestAdapter);
        // var nextPage = await nextPageRequest.GetAsync();
        var moreAvailable = !string.IsNullOrEmpty(userPage.OdataNextLink);

        Console.WriteLine($"\nMore users available? {moreAvailable}");
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Error getting users: {ex.Message}");
    }
}
// </ListUsersSnippet>

// <MakeGraphCallSnippet>
async Task MakeGraphCallAsync()
{
    await GraphHelper.MakeGraphCallAsync();
}
// </MakeGraphCallSnippet>