.net core 实现QQ登陆网站

   public const string appId = "";//QQ的APPID
        public const string appSecret = "";//QQ的appSecret
        public const string redirecturl = "";//回调地址

#region QQ登陆
        /// <summary>
        /// 打开qq授权页面
        /// </summary>
        /// <returns></returns>
        public virtual IActionResult QqAuthorize()
        {
          var url=string.Format(
                   "https://graph.qq.com/oauth2.0/authorize?response_type=code&client_id={0}&redirect_uri={1}&state=State",
                   appId, WebUtility.UrlEncode(redirecturl));
            return new RedirectResult(url);
        }
        /// <summary>
        /// QQ回掉方法
        /// </summary>
        /// <returns></returns>
        public virtual IActionResult QQLogin()
        {
            var code = Request.Query["code"];
            var token = GetAuthorityAccessToken(code);
            var dis = GetAuthorityOpendIdAndUnionId(token);
            var userInfo = GetUserInfo(token, dis["openid"]);
            return null;
        }


        public virtual string GetAuthorityAccessToken(string code)
        {
            if (string.IsNullOrEmpty(code))
                return null;
            var url =
                string.Format(
                    "https://graph.qq.com/oauth2.0/token?client_id={0}&client_secret={1}&code={2}&grant_type=authorization_code&redirect_uri={3}",
                    appId, appSecret, code, redirecturl);
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            var json =WebRequestHelper.GetResponse(request, "utf-8");
            if (string.IsNullOrEmpty(json))
                return null;
            if (!json.Contains("access_token"))
            {
                return null;
            }
            var dis = json.Split('&').Where(it => it.Contains("access_token")).FirstOrDefault();
            var accessToken = dis.Split('=')[1];
            return accessToken;
        }
        /// <summary>
        /// 获取OpenId和UnionId
        /// </summary>
        /// <param name="token"></param>
        /// <returns></returns>
        public virtual Dictionary<string, string> GetAuthorityOpendIdAndUnionId(string token)
        {
            if (string.IsNullOrEmpty(token)) return null;
            var url = $"https://graph.qq.com/oauth2.0/me?access_token={token}&unionid=1";
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.Method = "GET";
            request.ContentType = "application/x-www-form-urlencoded";
            var json =WebRequestHelper.GetResponse(request, "utf-8");
            if (string.IsNullOrEmpty(json) || json.Contains("error") || !json.Contains("callback"))
                return null;
            Regex reg = new Regex(@"(([^)]*))");
            Match m = reg.Match(json);
            var dis = m.Result("$1").DeserializeJson<Dictionary<string, string>>();
            return dis;
        }
        /// <summary>
        /// 获取用户的基本信息
        /// </summary>
        /// <param name="token"></param>
        /// <param name="openId"></param>
        /// <returns></returns>
        public virtual Dictionary<string, string> GetUserInfo(string token, string openId)
        {
            if (string.IsNullOrEmpty(token)) return null;
            var url = $"https://graph.qq.com/user/get_user_info?access_token={token}&openid={openId}&oauth_consumer_key={appId}";
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            var json =WebRequestHelper.GetResponse(request, "utf-8");
            var dis = json.DeserializeJson<Dictionary<string, string>>();
            if (dis.ContainsKey("ret") && dis["ret"] != "0")
                return null;
            return dis;
        }
        #endregion

//PS.

我的项目中不允许用户直接使用第三方登陆，所在在登陆的时候会给一个页面让用户绑定已有账号

在项目中遇到一个前端的知识盲区，就是如何关闭页面的同时刷新登陆页面。

用到的js很简单

  需关闭的页面
 document.domain='@Html.GetUrl("Domain")';//跨域
            var json = {
                Status:@Model.IsLogin.ToString().ToLower(),
            }
            window.opener.callbackQq(json)
            window.close();
需刷新的页面
window.callbackQq = function (result) {
    if (result.Status) {
        window.location.reload();
    }
    else {
        var _html = "";
        _html += '<span class="failure">请绑定账号，再使用第三方登陆</span>';
        $("#error").append(_html);
    }
}

登陆到这里应该算是完结了。