ITブログ時々なんでもブログ

Google.SignIn.SignIn.SharedInstance.SignedIn += (sender, e) => {
    // サインイン成功時の処理
    if (e.User != null && e.Error == null)
    {
        GoogleSignInService.MailAddress = e.User.Profile.Email;
        GoogleSignInService.AccessToken = e.User.Authentication.AccessToken;
    }
};

public void OnConnected(Bundle connectionHint)
{
    //接続成功時の処理が必要であれば記述します。
    Task.Run(() =>
    {
        try
        {
            GoogleSignInService.MailAddress = PlusClass.AccountApi.GetAccountName(GoogleSignInService.GoogleApiClient);
            GoogleSignInService.AccessToken = Android.Gms.Auth.GoogleAuthUtil.GetToken(
                                                this,
                                                new Android.Accounts.Account(GoogleSignInService.MailAddress, "com.google"),
                                                "oauth2:" + "https://www.googleapis.com/auth/calendar");
        }
        catch (Exception ex)
        {
            LogUtility.OutPutError(ex.Message + System.Environment.NewLine + ex.StackTrace);
        }
    }).ConfigureAwait(false);
}

using System.IO;
using System.Net;
using System.Net.Http;
async void OnGoogleCalendarClick(object sender, EventArgs e)
{
    string email = DependencyService.Get<IGoogleSignInService>().GetSignInMailAddress();
    string token = DependencyService.Get<IGoogleSignInService>().GetAccessToken();
    //カレンダーを取得します。
    string url = await this.GetGoogleCalendar(email, token);  
}

private const string GoogleCalendarUrlHome = "https://www.googleapis.com/calendar/v3";        

async Task<string> GetGoogleCalendar(string accountId, string token)
{
    string result = String.Empty;
    try
    {
        //URLを設定
        string url = this.GoogleCalendarUrlHome + 
                     this.GetCalendarEventUrl(accountId) + 
                     this.GetApiKeyUrl());

        /*******************************************************************/
        //①HttpClientを用いた接続例
        /*******************************************************************/
        var client = new System.Net.Http.HttpClient();
        //HTTPヘッダーに取得したトークンを設定
        client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);
        //URLを設定
        result = await client.GetStringAsync(url);

        /*******************************************************************/
        //②HttpWebRequestを用いた接続例
        /*******************************************************************/
        var httpWebRequest = HttpWebRequest.Create(url) as HttpWebRequest;
        httpWebRequest.Method = "GET";
        httpWebRequest.Accept = "*/*";
        httpWebRequest.CookieContainer = new CookieContainer();
        httpWebRequest.Headers["Authorization"] = String.Format("Bearer {0}", token);   //HTTPヘッダーに取得したトークンを設定
        using (HttpWebResponse response = await httpWebRequest.GetResponseAsync() as HttpWebResponse)
        {
            Stream stream = response.GetResponseStream();
            using (StreamReader reader = new StreamReader(stream))
            {
                result = reader.ReadToEnd();
            }
        }

        return Newtonsoft.Json.JsonConvert.DeserializeObject<EventInfo>(result).ToString();

    }
    catch (System.Net.Http.HttpRequestException hre)
    {
        //サインインしていないと認証エラーが発生する場合がある
        return hre.Message;
    }
    catch (Exception ex)
    {
        System.Diagnostics.Debug.WriteLine(ex.Message + System.Environment.NewLine + ex.StackTrace);
        return ex.Message;
    }
}

//URLは以下を参照
//https://developers.google.com/google-apps/calendar/v3/reference/

//カレンダーを取得するURL
string GetCalendarUrl(string accountId)
{
    const string url = "/users/me/calendarList/{0}";
    return String.Format(url, accountId);
}
//イベントを取得するURL
string GetCalendarEventUrl(string accountId)
{
    const string url = "/calendars/{0}/events";
    return String.Format(url, accountId);
}
//URLにAPI_KEYを設定する
private static string GetApiKeyUrl()
{
    if (Device.RuntimePlatform == Device.iOS)
    {
        //Google API Console でWebアプリケーションに設定したAPI_KEYをここに貼り付ける
        return "?key=AIzaSyxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"; 
    }
    else if (Device.RuntimePlatform == Device.Android)
    {
        //Google API Console でWebアプリケーションに設定したAPI_KEYをここに貼り付ける
        return "?key=AIzaSyxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    }
    return String.Empty;
}