public class weixin_helper
 {
  public weixin_helper()
  {
  }
  /// <summary>
  /// 根據(jù)AppID和AppSecret獲得access token(默認(rèn)過期時(shí)間為2小時(shí))
  /// </summary>
  /// <returns>Dictionary</returns>
  public static Dictionary<string, object> get_access_token()
  {
   //獲得配置信息
   oauth_config config = oauth_helper.get_config(2);
   string send_url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" +
        config.oauth_app_id + "&secret=" + config.oauth_app_key + "";
   //發(fā)送并接受返回值
   string result = Utils.HttpGet(send_url);
   if (result.Contains("errmsg"))
   {
    return null;
   }
   try
   {
    Dictionary<string, object> dic = JsonConvert.DeserializeObject<Dictionary<string, object>>(result);
    return dic;
   }
   catch
   {
    return null;
   }
  } /// <summary>
  /// 取得臨時(shí)的Access Token(默認(rèn)過期時(shí)間為2小時(shí))
  /// </summary>
  /// <param name="code">臨時(shí)Authorization Code</param>
  /// <param name="state">防止CSRF攻擊，成功授權(quán)后回調(diào)時(shí)會原樣帶回</param>
  /// <returns>Dictionary</returns>
  public static Dictionary<string, object> get_access_token(string code, string state)
  {
   //獲得配置信息
   oauth_config config = oauth_helper.get_config(2);
   string send_url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=" +
        config.oauth_app_id + "&secret=" + config.oauth_app_key + "&code="+code+"&grant_type=authorization_code";
   //發(fā)送并接受返回值
   string result = Utils.HttpGet(send_url);
   if (result.Contains("errmsg"))
   {
    return null;
   }
   try
   {
    Dictionary<string, object> dic = JsonConvert.DeserializeObject<Dictionary<string, object>>(result);
    return dic;
   }
   catch
   {
    return null;
   }
  }
  /// <summary>
  /// 根據(jù)access_token判斷access_token是否過期
  /// </summary>
  /// <param name="access_token"></param>
  /// <returns>true表示未失效</returns>
  public static bool check_access_token(string access_token)
  {
   //獲得配置信息
   oauth_config config = oauth_helper.get_config(2);
   string send_url = "https://api.weixin.qq.com/sns/auth?access_token=" + access_token + "&openid=" + config.oauth_app_id;
   //發(fā)送并接受返回值
   string result = Utils.HttpGet(send_url);
   try
   {
    Dictionary<string, object> dic = JsonConvert.DeserializeObject<Dictionary<string, object>>(result);
    if (dic.ContainsKey("errmsg"))
    {
     if (dic["errmsg"].ToString()=="ok")
     {
      return true;
     }
     else
     {
      return false;
     }
    }
    return false;
   }
   catch
   {
    return false;
   }
  }
  /// <summary>
  /// 若fresh_token已過期則根據(jù)refresh_token取得新的refresh_token
  /// </summary>
  /// <param name="refresh_token">refresh_token</param>
  /// <returns>Dictionary</returns>
  public static Dictionary<string, object> get_refresh_token(string refresh_token)
  {
   //獲得配置信息
   oauth_config config = oauth_helper.get_config(2);
   string send_url =
    "https://api.weixin.qq.com/sns/oauth2/refresh_token?appid=" +
        config.oauth_app_id + "&grant_type=refresh_token&refresh_token=" + refresh_token;
   //發(fā)送并接受返回值
   string result = Utils.HttpGet(send_url);
   if (result.Contains("errmsg"))
   {
    return null;
   }
   try
   {
    Dictionary<string, object> dic = JsonConvert.DeserializeObject<Dictionary<string, object>>(result);
    return dic;
   }
   catch
   {
    return null;
   }
  }
  /// <summary>
  /// 獲取登錄用戶自己的基本資料
  /// </summary>
  /// <param name="access_token">臨時(shí)的Access Token</param>
  /// <param name="open_id">用戶openid</param>
  /// <returns>Dictionary</returns>
  public static Dictionary<string, object> get_user_info(string access_token, string open_id)
  {
   //獲得配置信息
   oauth_config config = oauth_helper.get_config(2);
   //發(fā)送并接受返回值 
   string send_url = "https://api.weixin.qq.com/sns/userinfo?access_token="+access_token+"&openid="+open_id;
   //發(fā)送并接受返回值
   string result = Utils.HttpGet(send_url);
   if (result.Contains("errmsg"))
   {
    return null;
   }
   //反序列化JSON
   Dictionary<string, object> dic = JsonHelper.DataRowFromJSON(result);
   return dic;
  }
 }

#region 微信登錄
  /// <summary>
  /// 微信登錄
  /// </summary>
  public ActionResult WeChat()
  {
   //獲得配置信息
   oauth_config config = oauth_helper.get_config(2); //主鍵id
   if (config == null)
   {
    return Content("出錯(cuò)了，您尚未配置微信相關(guān)的API信息！");
   }
   string state = Guid.NewGuid().ToString().Replace("-", "");
   Session["oauth_state"] = state;
   string send_url =
    "https://open.weixin.qq.com/connect/qrconnect?appid=" + config.oauth_app_id +
        "&redirect_uri=" + Utils.UrlEncode(config.return_uri.ToLower()) +
        "&response_type=code&scope=snsapi_login&state=" + state +
        "#wechat_redirect";
   //開始發(fā)送
   return Redirect(send_url); //跳轉(zhuǎn)到微信自己 指定的關(guān)聯(lián)登陸頁面
  }
  /// <summary>
  /// 微信登錄返回action
  /// </summary>
  public ActionResult WeChatReturnUrl(string state, string code)
  {
   //取得返回參數(shù)
   string access_token = string.Empty;
   string expires_in = string.Empty;
   string client_id = string.Empty;
   string openid = string.Empty;
   string refresh_token = string.Empty;
   if (Session["oauth_state"] == null || Session["oauth_state"].ToString() == "" ||
    state != Session["oauth_state"].ToString() || string.IsNullOrEmpty(code))//若返回參數(shù)中未包含code或者state沒有通過驗(yàn)證則提示出錯(cuò)
   {
    return Content("出錯(cuò)啦，state未初始化！");
   }
   //第一步：通過code來獲取Access Token以及openid
   Dictionary<string, object> dic1 = weixin_helper.get_access_token(code, state);
   if (dic1 == null || !dic1.ContainsKey("access_token"))
   {
    return Content("錯(cuò)誤代碼：，無法獲取Access Token，請檢查App Key是否正確！");
   }
   if (dic1 == null || !dic1.ContainsKey("openid"))
   {
    if (dic1.ContainsKey("errmsg"))
    {
     return Content("errcode：" + dic1["errcode"] + ",errmsg：" + dic1["errmsg"]);
    }
    else
    {
     return Content("出錯(cuò)啦，無法獲取用戶授權(quán)Openid！");
    }
   }
   access_token = dic1["access_token"].ToString();//獲取access_token
   expires_in = dic1["expires_in"].ToString();//獲取過期時(shí)間
   refresh_token = dic1["refresh_token"].ToString();//獲取用于重新刷新access_token的憑證
   openid = dic1["openid"].ToString();//用戶唯一標(biāo)示openid
   //儲存獲取數(shù)據(jù)用到的信息
   Session["oauth_name"] = "webchat";
   Session["oauth_access_token"] = access_token;
   Session["oauth_openid"] = openid;
   Session["oauth_refresh_token"] = refresh_token;
   #region todo 將獲取到的用戶信息保存到數(shù)據(jù)庫中
   #endregion
   //第二步：通過Access Token以及openid來獲取用戶的基本信息
   //Dictionary<string, object> dic2 = weixin_helper.get_user_info(access_token,openid);
   //第三步：跳轉(zhuǎn)到指定頁面
   return Content(WeChatResultJson());
  }
  /// <summary>
  /// 微信登錄返回action, 處理用戶信息
  /// </summary>
  public string WeChatResultJson()
  {
   string oauth_access_token = string.Empty;
   string oauth_openid = string.Empty;
   string oauth_name = string.Empty;
   string oauth_refresh_token = string.Empty;
   if (Session["oauth_name"] == null || Session["oauth_access_token"] == null ||
    Session["oauth_openid"] == null)
   {
    return "{\"ret\":\"1\", \"msg\":\"出錯(cuò)啦，Access Token已過期或不存在！\"}";
   }
   oauth_name = Session["oauth_name"].ToString();
   oauth_access_token = Session["oauth_access_token"].ToString();
   oauth_openid = Session["oauth_openid"].ToString();
   oauth_refresh_token = Session["oauth_refresh_token"].ToString();
   if (!weixin_helper.check_access_token(oauth_access_token)) //調(diào)用access_token前需判斷是否過期
   {
    Dictionary<string, object> dic1 = weixin_helper.get_refresh_token(oauth_refresh_token);//如果已過期則重新?lián)Q取新的access_token
    if (dic1 == null || !dic1.ContainsKey("access_token"))
    {
     return "{\"openid\":\"0\", \"msg\":\"出錯(cuò)啦，無法獲取access_token！\"}";
    }
    oauth_access_token = dic1["access_token"].ToString();
   }
   Dictionary<string, object> dic = weixin_helper.get_user_info(oauth_access_token, oauth_openid);
   if (dic == null)
   {
    return "{\"openid\":\"0\", \"msg\":\"出錯(cuò)啦，無法獲取授權(quán)用戶信息！\"}";
   }
   try
   {
    StringBuilder str = new StringBuilder();
    str.Append("{");
    str.Append("\"openid\": \"" + dic["openid"].ToString() + "\", ");
    str.Append("\"nickname\": \"" + dic["nickname"].ToString() + "\", ");
    str.Append("\"sex\": \"" + dic["sex"].ToString() + "\", ");
    str.Append("\"province\": \"" + dic["province"].ToString() + "\", ");
    str.Append("\"city\": \"" + dic["city"].ToString() + "\", ");
    str.Append("\"country\": \"" + dic["country"].ToString() + "\", ");
    str.Append("\"headimgurl\": \"" + dic["headimgurl"].ToString() + "\", ");
    str.Append("\"privilege\": \"" + dic["privilege"].ToString() + "\", ");
    str.Append("\"unionid\": \"" + dic["unionid"].ToString() + "\"");
    str.Append("\"oauth_name\": \"" + oauth_name + "\"");
    str.Append("\"oauth_access_token\": \"" + oauth_access_token + "\"");
    str.Append("\"oauth_openid\": \"" + oauth_openid + "\"");
    str.Append("}");
    return str.ToString();
   }
   catch
   {
    return "{\"ret\":\"0\", \"msg\":\"出錯(cuò)啦，無法獲取授權(quán)用戶信息！\"}";
   }
  }
  #endregion