饅頭小舖

public class FacebookScopedClient : IAuthenticationClient
{
    private string appId;
    private string appSecret;

    //設置基礎連結，顯示驗證視窗的對話方塊
    private const string BaseUrl = "https://www.facebook.com/dialog/oauth?client_id=";
    //設置基礎連結，取得Token
    public const string GraphApiToken = "https://graph.facebook.com/oauth/access_token?";
    //設置基礎連結，取得使用者資料
    public const string GraphApiMe = "https://graph.facebook.com/me?";

    /// <summary>
    /// 【私用】取得要求頁面的網頁資訊
    /// </summary>
    /// <param name="URL">要求的連結</param>
    /// <returns></returns>
    private static string GetHTML(string URL)
    {
        string ConnectionString = URL;

        try
        {
            // 向對方Server傳送要求
            System.Net.HttpWebRequest MyRequest = (HttpWebRequest)WebRequest.Create(ConnectionString);
            MyRequest.Credentials = CredentialCache.DefaultCredentials;
            //// 取得網站的回應
            WebResponse WebResponse = MyRequest.GetResponse();
            Stream ResponeStream = WebResponse.GetResponseStream();
            ////開啟資料讀取串流
            StreamReader IOStream = new StreamReader(ResponeStream);
            string PageContent = IOStream.ReadToEnd();
            //// 關閉串流
            IOStream.Close();
            ResponeStream.Close();
            return PageContent;
        }
        catch (Exception)
        {
        }
        return null;
    }

    /// <summary>
    /// 解析使用者資料
    /// </summary>
    /// <param name="AccessCode">資料授權碼</param>
    /// <param name="RedirectURI">返回的頁面連結</param>
    /// <returns></returns>
    private IDictionary<string, string> GetUserData(string AccessCode, string RedirectURI)
    {
        //取得授權Token
        string Token = GetHTML(GraphApiToken + "client_id=" + appId + "&redirect_uri=" + HttpUtility.UrlEncode(RedirectURI) + "&client_secret=" + appSecret + "&code=" + AccessCode);
        if (Token == null || Token == "")//若Token是null或空白，表示驗證失敗
        {
            return null;
        }
        //向Facebook傳送要求，取得使用者資料，fields則放置你所需要的資料
        string Data = GetHTML(GraphApiMe + "fields=id,name,email,username,gender,link,birthday&access_token=" + Substring(Token, "access_token=", "&"));

        //解析Facebook傳回的使用者資料，Facebook傳回的是Json格式的資料，我們這邊利用Json.net這個套件解析Json
        //Json.net則可以透過NuGet取得
        Dictionary<string, string> UserData = JsonConvert.DeserializeObject<Dictionary<string, string>>(Data);
        return UserData;
    }


    /// <summary>
    /// 初始化
    /// </summary>
    /// <param name="appId">授權代碼</param>
    /// <param name="appSecret">授權安全碼</param>
    public FacebookScopedClient(string appId, string appSecret)
    {
        this.appId = appId;
        this.appSecret = appSecret;
    }

    /// <summary>
    /// 傳回供應商名稱
    /// </summary>
    public string ProviderName
    {
        get { return "Facebook"; }
    }

    /// <summary>
    /// 導向Facebook驗證授權頁面
    /// </summary>
    /// <param name="Context">Http要求資訊</param>
    /// <param name="ReturnUrl">通過授權後導回的頁面</param>
    public void RequestAuthentication(System.Web.HttpContextBase Context, Uri ReturnUrl)
    {
        string Url = BaseUrl + appId + "&redirect_uri=" + HttpUtility.UrlEncode(ReturnUrl.ToString()) + "&scope=email,user_birthday,user_location,publish_actions";
        Context.Response.Redirect(Url);
    }

    /// <summary>
    /// 傳回授權狀態與授權資料
    /// </summary>
    /// <param name="Context">Http要求資訊</param>
    /// <returns>授權狀態與授權資料</returns>
    public AuthenticationResult VerifyAuthentication(System.Web.HttpContextBase Context)
    {
        string Code = Context.Request.QueryString["code"];

        string RawUrl = Context.Request.Url.OriginalString;

        RawUrl = Regex.Replace(RawUrl, "&code=[^&]*", "");

        IDictionary<string, string> UserData = this.GetUserData(Code, RawUrl);

        //假如使用者資訊為空白，就傳回驗證失敗
        if (UserData == null)
            return new AuthenticationResult(false, ProviderName, null, null, null);

        string id = UserData["id"];
        string UserName = UserData["username"];
        UserData.Remove("id");
        UserData.Remove("username");

        return new AuthenticationResult(true, ProviderName, id, UserName, UserData);
    }

    /// <summary>
    /// 私用，擷取部分字串資料
    /// </summary>
    /// <param name="Str">原始字串</param>
    /// <param name="StartString">開始擷取的字串內容</param>
    /// <param name="EndString">結束擷取的字串內容</param>
    /// <returns>原始字串的內容</returns>
    private string Substring(string Str, string StartString, string EndString)
    {
        if (Str.Contains(StartString))
        {
            int iStart = Str.IndexOf(StartString) + StartString.Length;
            int iEnd = Str.IndexOf(EndString, iStart);
            return Str.Substring(iStart, (iEnd - iStart));
        }
        return null;
    }
}

OAuthWebSecurity.RegisterClient(new FacebookScopedClient("appId", "appSecret"), "Facebook", null);