---
title : Google.Apis.Calendar.v3
tags: Google.Apis.Calendar.v3
creat-date: 2022-01-19
update_date : 2022-01-19
---

---
# 使用 Google.Apis.Calendar.v3
---

## 步驟一：取得授權

**1.建立 Google 一個專案，申請網址：**
https://console.developers.google.com/projectselector/apis/library?supportedpurview=project

**2.專案建立完成後「建立憑證」，選擇「OAuth用戶端ID」**

**3.填寫相關資料，「已授權的重新導向URI」一定要填寫**

**4.下載JSON，並在系統程式中建立一個資料夾GoogleStorage存放檔案「client_secret.json」**

**5.Nuget 下載 Google.Apis.Calendar.v3 套件**

**6.點擊授權後的程式碼**

protected void btnStart_Click(object sender, EventArgs e)
{
    GoogleClientSecrets clientSecret;
    //匯入專案憑證
    using (var stream = new FileStream(Gfolder + @"\client_secret.json", FileMode.Open, FileAccess.Read)) {
        clientSecret = GoogleClientSecrets.Load(stream);
    }

    //建立流程權限
    IAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow(
    new GoogleAuthorizationCodeFlow.Initializer {
        ClientSecrets = clientSecret.Secrets,
        DataStore = new FileDataStore(Gfolder),
        Scopes = new[] { CalendarService.Scope.Calendar }
    });

    var uri = System.Web.HttpContext.Current.Request.Url.ToString();
    var result = new AuthorizationCodeWebApp(flow, uri, "success").AuthorizeAsync(UserId, CancellationToken.None).Result;
    if (result.RedirectUri != null) {
        //導去授權頁
        Response.Redirect(result.RedirectUri);
    }
}

**從Google 授權後回來的處理**

/// <summary>App 憑證資料的檔案夾</summary>
public static string Gfolder = AppDomain.CurrentDomain.BaseDirectory + "GoogleStorage" + System.IO.Path.DirectorySeparatorChar;   
/// <summary>通常在就是用戶的資料庫 id</summary>
public static string UserId = "CSMS";

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack) {
        GoogleClientSecrets clientSecret;

        using (var stream = new FileStream(Gfolder + @"\client_secret.json", FileMode.Open, FileAccess.Read))
        {
            clientSecret = GoogleClientSecrets.Load(stream);
        }

        IAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow(
                                      new GoogleAuthorizationCodeFlow.Initializer
                                      {
                                            ClientSecrets = clientSecret.Secrets,
                                            DataStore = new FileDataStore(Gfolder),
                                            Scopes = new[] { CalendarService.Scope.Calendar }
                                      });

        var uri = HttpContext.Current.Request.Url.ToString();
        var code = HttpContext.Current.Request["code"];
        if (code != null)
        {
            var token = flow.ExchangeCodeForTokenAsync(UserId, code,
                           uri.Substring(0, uri.IndexOf("?")), CancellationToken.None).Result;

            //儲存使用者的Token
            var oauthState = AuthWebUtility.ExtracRedirectFromState(
                flow.DataStore, UserId, Request["state"]).Result;

            //印出儲存狀態
            Response.Write(oauthState);
        }
    }
}

**7.執行結果**

**成功回來後，會在資料夾「GoogleStorage」看到多一個檔案 : Google.Apis.Auth.OAuth2.Responses.TokenResponse-CSMS
(我的UserId = "CSMS"，所以檔名會是CSMS)**

## 步驟二：交換 Token

### **說明：access_token 只能存活一小時，需要跟 google 再重新交換以取得新的Token。**

/// <summary>App 憑證資料的檔案夾</summary>
public static string Gfolder = AppDomain.CurrentDomain.BaseDirectory + "GoogleStorage" + System.IO.Path.DirectorySeparatorChar;   
/// <summary>通常在就是用戶的資料庫 id </summary>
public static string UserId = "CSMS";
    
protected void btnRefreshToken_Click(object sender, EventArgs e)
    {
        var userAccessToken = JsonConvert.DeserializeObject<GoogleTokenModel>(File.ReadAllText(Gfolder + "Google.Apis.Auth.OAuth2.Responses.TokenResponse-" + UserId));
        try {
            using (var wb = new WebClient()) {
                var data = new NameValueCollection();
                data["refresh_token"] = userAccessToken.refresh_token;
                data["client_id"] = "000000000-xxxxxxxxx.apps.googleusercontent.com";
                data["client_secret"] = "xxxxxxxxx";
                data["grant_type"] = "refresh_token";

                var response = wb.UploadValues("https://accounts.google.com/o/oauth2/token?", "POST", data);
                string responseUTF8 = System.Text.Encoding.UTF8.GetString(response);

                var changeTokenResponse = JsonConvert.DeserializeObject<GoogleTokenModel>(responseUTF8);

                Response.Write("Token 從原本的 :" + userAccessToken.access_token + " 換成: " + changeTokenResponse.access_token);

                userAccessToken.access_token = changeTokenResponse.access_token;
                File.WriteAllText(Gfolder + "Google.Apis.Auth.OAuth2.Responses.TokenResponse-" + UserId, JsonConvert.SerializeObject(userAccessToken));
            }
        }
        catch (Exception ex) {
            Response.Write(ex.Message);
        }
    }

## 步驟三：新增、刪除、取得資料範例

/// <summary>App 憑證資料的檔案夾</summary>
public static string Gfolder = AppDomain.CurrentDomain.BaseDirectory + "GoogleStorage" + System.IO.Path.DirectorySeparatorChar;

/// <summary>通常在就是用戶的資料庫 id </summary>
public static string UserId = "CSMS";

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack) {
        RefreshToken(); // 重新取得 Google Token
    }
}

/// <summary>
/// 重新取得 Google Token
/// </summary>
protected void RefreshToken()
{
    ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls12;
    var userAccessToken = JsonConvert.DeserializeObject<GoogleTokenModel>(File.ReadAllText(Gfolder + "Google.Apis.Auth.OAuth2.Responses.TokenResponse-" + UserId));
    try {
        using (var wb = new WebClient()) {
            var data = new NameValueCollection();
            data["refresh_token"] = userAccessToken.refresh_token;
            data["client_id"] = "00000000-xxxxxx.apps.googleusercontent.com";
            data["client_secret"] = "XXXXXXXXXXX";
            data["grant_type"] = "refresh_token";

            var response = wb.UploadValues("https://accounts.google.com/o/oauth2/token?", "POST", data);
            string responseUTF8 = System.Text.Encoding.UTF8.GetString(response);
            var changeTokenResponse = JsonConvert.DeserializeObject<GoogleTokenModel>(responseUTF8);
            //Response.Write("Token 從原本的 :" + userAccessToken.access_token + " 換成: " + changeTokenResponse.access_token);
            userAccessToken.access_token = changeTokenResponse.access_token;
            File.WriteAllText(Gfolder + "Google.Apis.Auth.OAuth2.Responses.TokenResponse-" + UserId, JsonConvert.SerializeObject(userAccessToken));
        }
    }
    catch (Exception ex) {
        //Response.Write(ex.Message);
    }
}

/// <summary>
/// 新增行事曆資料[測試]
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void btnAddCalendar_Click(object sender, EventArgs e)
{
    Event event1 = new Event() {
        Summary = "隨身秘書[測試]",
        Location = "立法院群賢樓202會議室",
        Description = "主持人：張廖萬堅<br/>本局與會人員：堅測管理組坡地管理科周玉奇科長、農村建設組農村規劃科陳明賢科長",
        Start = new EventDateTime() {
            DateTime = new DateTime(2019, 12, 31),
            TimeZone = "Asia/Taipei"
        },
        End = new EventDateTime() {
            DateTime = new DateTime(2019, 12, 31).AddHours(1),
            TimeZone = "Asia/Taipei"
        },
    };

    var d = JsonConvert.DeserializeObject<GoogleTokenModel>(File.ReadAllText(Gfolder + "Google.Apis.Auth.OAuth2.Responses.TokenResponse-" + UserId));
    CalendarService calService = GetCalendarService(d);
    EventsResource eventResource = new EventsResource(calService);

    var insertEntry = eventResource.Insert(event1, "primary").Execute();
    txtEventId.Text = insertEntry.Id;
}
/// <summary>
/// 刪除行事曆資料[測試]
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void btnDel_Click(object sender, EventArgs e)
{
    var d = JsonConvert.DeserializeObject<GoogleTokenModel>(File.ReadAllText(Gfolder + "Google.Apis.Auth.OAuth2.Responses.TokenResponse-" + UserId));
    CalendarService calService = GetCalendarService(d);
    EventsResource eventResource = new EventsResource(calService);

    eventResource.Delete("primary", txtEventId.Text).Execute();
    Response.Write("成功刪除 :" + txtEventId.Text);
}

/// <summary>
/// 取得日期區間的行事曆[測試]
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
protected void btnRequest_Click(object sender, EventArgs e)
{
    var d = JsonConvert.DeserializeObject<GoogleTokenModel>(File.ReadAllText(Gfolder + "Google.Apis.Auth.OAuth2.Responses.TokenResponse-" + UserId));
    CalendarService calService = GetCalendarService(d);       

    EventsResource.ListRequest listRequest = new EventsResource.ListRequest(calService, "primary");
    listRequest.TimeMin = new DateTime(2019, 12, 31);
    listRequest.TimeMax = new DateTime(2019, 12, 31);
    listRequest.ShowDeleted = false;
    listRequest.SingleEvents = true;
    listRequest.OrderBy = EventsResource.ListRequest.OrderByEnum.StartTime;

    Events events = listRequest.Execute();
    string response = "";
    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;
            }
            string sContent = string.Format("時間：{0}<br/>主旨：{1}<br/>地點：{2}<br/>內容：{3}", when, eventItem.Summary, eventItem.Location, eventItem.Description);               
            response += sContent + "<br/>";
        }
    }
    Response.Write("取得資料 :<br/><br/>" + response);
}
    

## 步驟四：防火牆使用申請
(1) accounts.google.com
(2) oauth2.googleapis.com
(3) www.googleapis.com

## 測試執行畫面

**1.新增資料**


**2.取得行事曆資料**


**3.刪除資料**

## 參考來源：
(1)憑證授權：https://blog.no2don.com/2017/12/caspnet-googleapiscalendarv3.html
(2)新增刪除：https://blog.no2don.com/2017/12/caspnet-googleapiscalendarv3_19.html
(3)交換Token：https://blog.no2don.com/2017/12/caspnet-googleapiscalendarv3-token.html