Google Calendar API with ASP.NET

问题:

I'm confused about using the Google Calendar API for adding/modifying events in ASP.NET webforms (C#).

I'm not sure if I need oAuth or what. My app is on my own server accessing my own domain and my own calendar. I don't need other users to give me access to their calendar; I only need to access my own via my app.

On on one of my aspx pages, I'd like to send event info to my Google calendar to add (or later modify) the event.

I've checked all kinds of code examples and the Google getting started guides. I'm just not clear on what exactly is needed. I've set up an API key and an oAuth2 client ID. The Google instructions have sent me in circles and it's likely due to my needing clarification on what's need.

Can someone please clear-up my confusion and point me in the right direction?

回答1:

Summary :

• To Call a google clould oauth2 protected resource

• From your server to google server

• Without user interaction

• Accessing your own data

• Using C#

Code :

    var private_key = @"-----BEGIN PRIVATE KEY-ccc-END PRIVATE KEY-----\n";
    string calendarId = @"[e-mail]";
    var client_email = @"[e-mail]";

    var credential =
        new ServiceAccountCredential(
        new ServiceAccountCredential.Initializer(client_email)
        {
            Scopes = new string[] { CalendarService.Scope.Calendar }
        }.FromPrivateKey(private_key));
    var service = new CalendarService(new BaseClientService.Initializer()
    {
        HttpClientInitializer = credential,
    });

• Use service methods to get the data

• Private Key and client_email can be generated from this link

• Calendar Id can be found on calendar.google.com

• You must share your calendar with client_email see the demo

---

  Google            You                             You
  Pay +             Pay +                           Pay +
  Google            Google                          You
  Manage            Manage                          Manage%
 +----------+    +----------+                     +----------+
 | Gmail    |    |          |                     |          |
 | Calendar |    |  G Suite |                     | Google   |
 | drive    |    |          |                     | Cloud    |
 |          |    |          |                     |          |
 +----^-----+    +----+-----+                     +------+---+
      |               ^                                  ^
      |               |                                  |
      |               |                                  |
      |               |                                  |
+-------------------------------------------------------------+
|     |               |                                  |    |
|     |               |                                  |    |
|     |               |       Google                     |    |
|     |               |       Oauth2                     |    |
|     |               |       Server                     |    |
|     |               |                                  |    |
|     |               |                                  |    |
+-------------------------------------------------------------+
      |               |                                  |
      |               |         +----------------+       |
      |               |         |                |       |
      |               |         |                |       | No
      |               |require  |                |       | Consent
      |               |admin    |                |       |
      |               |consent  |                |       |
      |require        |         |                +-------+
      |user           |         |                |
      |consent        +---------+   Your app     |
      |                         |                |
      |                         |                |
      |                         |                |
      |                         |                |
      +-------------------------+                |
                                |                |
                                |                |
                                |                |
                                +----------------+
                                     You
                                     Pay +
                                     You
                                     Manage

---

Step by Step demo

---

Step 01 : open google console

https://console.developers.google.com/projectselector/apis/library/calendar-json.googleapis.com

Step 02 : click select

Step 03: select or create a new project

Step 04: click enable or manage

Step 05: click Credentials

Step 06: Create service account key

Step 07: Enter a service account name the click create

Step 08: click Create without role then keep the downloaded json private key in safe place

Step 09: copy your client_email from

Step 10: open google calendar

• calendar.google.com

Step 11: open your calendar Settings and sharing

Step 12: got to Share with specific people and click add

Step 13:

1. Add the email for the service account that you copied before in step 09
2. change the Permissions too Make changes and manage sharing

3. click send

   

Step 14: on the same page copy and save the Calendar ID we will need it

Step 15: crate new console application

Step 16: add the private key json file to your project

Step 17: r-click private key json and click Propertis

Step 18: change "Copy to output Direcory to "Copy always"

Step 19: open PM Console and chose your project on Default project D

Step 20: Install Google.Apis Calendar Package

Install-Package Google.Apis.Calendar.v3

Step 21: replace Program.cs with code

using Google.Apis.Auth.OAuth2;
using Google.Apis.Calendar.v3;
using Google.Apis.Calendar.v3.Data;
using Google.Apis.Services;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

namespace CalendarQuickstart
{
    class Program
    {
        static void Main(string[] args)
        {
            string jsonFile = "xxxxxxx-xxxxxxxxxxxxx.json";
            string calendarId = @"[e-mail]";

            string[] Scopes = { CalendarService.Scope.Calendar };

            ServiceAccountCredential credential;

            using (var stream =
                new FileStream(jsonFile, FileMode.Open, FileAccess.Read))
            {
                var confg = Google.Apis.Json.NewtonsoftJsonSerializer.Instance.Deserialize<JsonCredentialParameters>(stream);
                credential = new ServiceAccountCredential(
                   new ServiceAccountCredential.Initializer(confg.ClientEmail)
                   {
                       Scopes = Scopes
                   }.FromPrivateKey(confg.PrivateKey));
            }

            var service = new CalendarService(new BaseClientService.Initializer()
            {
                HttpClientInitializer = credential,
                ApplicationName = "Calendar API Sample",
            });

            var calendar = service.Calendars.Get(calendarId).Execute();
            Console.WriteLine("Calendar Name :");
            Console.WriteLine(calendar.Summary);

            Console.WriteLine("click for more .. ");
            Console.Read();


            // Define parameters of request.
            EventsResource.ListRequest listRequest = service.Events.List(calendarId);
            listRequest.TimeMin = DateTime.Now;
            listRequest.ShowDeleted = false;
            listRequest.SingleEvents = true;
            listRequest.MaxResults = 10;
            listRequest.OrderBy = EventsResource.ListRequest.OrderByEnum.StartTime;

            // List events.
            Events events = listRequest.Execute();
            Console.WriteLine("Upcoming events:");
            if (events.Items != null && events.Items.Count > 0)
            {
                foreach (var eventItem in events.Items)
                {
                    string when = eventItem.Start.DateTime.ToString();
                    if (String.IsNullOrEmpty(when))
                    {
                        when = eventItem.Start.Date;
                    }
                    Console.WriteLine("{0} ({1})", eventItem.Summary, when);
                }
            }
            else
            {
                Console.WriteLine("No upcoming events found.");
            }
            Console.WriteLine("click for more .. ");
            Console.Read();

            var myevent = DB.Find(x => x.Id == "eventid" + 1);

            var InsertRequest = service.Events.Insert(myevent, calendarId);

            try
            {
                InsertRequest.Execute();
            }
            catch (Exception)
            {
                try
                {
                    service.Events.Update(myevent, calendarId, myevent.Id).Execute();
                    Console.WriteLine("Insert/Update new Event ");
                    Console.Read();

                }
                catch (Exception)
                {
                    Console.WriteLine("can't Insert/Update new Event ");

                }
            }
        }


        static List<Event> DB =
             new List<Event>() {
                new Event(){
                    Id = "eventid" + 1,
                    Summary = "Google I/O 2015",
                    Location = "800 Howard St., San Francisco, CA 94103",
                    Description = "A chance to hear more about Google's developer products.",
                    Start = new EventDateTime()
                    {
                        DateTime = new DateTime(2019, 01, 13, 15, 30, 0),
                        TimeZone = "America/Los_Angeles",
                    },
                    End = new EventDateTime()
                    {
                        DateTime = new DateTime(2019, 01, 14, 15, 30, 0),
                        TimeZone = "America/Los_Angeles",
                    },
                     Recurrence = new List<string> { "RRULE:FREQ=DAILY;COUNT=2" },
                    Attendees = new List<EventAttendee>
                    {
                        new EventAttendee() { Email = "[e-mail]"},
                        new EventAttendee() { Email = "[e-mail]"}
                    }
                }
             };
    }
}

Step 22: replace json File Name with your json file name

  string jsonFile = "xxxxxxx-xxxxxxxx.json";

Step 23: replace calendarId with your calendarId from step 14

 string calendarId = @"[e-mail]";

Step 24: run the app

Step 25 : visit you calendar you should see the event in

 2019/01/13