微信开放平台之网站授权微信登录功能

1 微信开放平台：

2 微信官方教程：https://open.weixin.qq.com/cgi-bin/showdocument?action=dir_list&t=resource/res_list&verify=1&id=open1419316505&token=&lang=zh_cn

3.pc页面显示

4. 通过官方提供的文档，我们可以看出一共分4个步骤

第一步：请求code

第二步：通过code获取access_token

第三步：通过access_token调用接口

第4步：获取用户个人信息（unionid机制）

api：核心代码

public class weixin_helper
 {
  public weixin_helper()
  {
  }
  /// <summary>
  /// 根据appid和appsecret获得access token(默认过期时间为2小时)
  /// </summary>
  /// <returns>dictionary</returns>
  public static dictionary<string, object> get_access_token()
  {
   //获得配置信息
   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 + "";
   //发送并接受返回值
   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>
  /// 取得临时的access token(默认过期时间为2小时)
  /// </summary>
  /// <param name="code">临时authorization code</param>
  /// <param name="state">防止csrf攻击，成功授权后回调时会原样带回</param>
  /// <returns>dictionary</returns>
  public static dictionary<string, object> get_access_token(string code, string state)
  {
   //获得配置信息
   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";
   //发送并接受返回值
   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>
  /// 根据access_token判断access_token是否过期
  /// </summary>
  /// <param name="access_token"></param>
  /// <returns>true表示未失效</returns>
  public static bool check_access_token(string access_token)
  {
   //获得配置信息
   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;
   //发送并接受返回值
   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已过期则根据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)
  {
   //获得配置信息
   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;
   //发送并接受返回值
   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>
  /// 获取登录用户自己的基本资料
  /// </summary>
  /// <param name="access_token">临时的access token</param>
  /// <param name="open_id">用户openid</param>
  /// <returns>dictionary</returns>
  public static dictionary<string, object> get_user_info(string access_token, string open_id)
  {
   //获得配置信息
   oauth_config config = oauth_helper.get_config(2);
   //发送并接受返回值 
   string send_url = "https://api.weixin.qq.com/sns/userinfo?access_token="+access_token+"&openid="+open_id;
   //发送并接受返回值
   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;
  }
 }

控制器的核心代码：

#region 微信登录
  /// <summary>
  /// 微信登录
  /// </summary>
  public actionresult wechat()
  {
   //获得配置信息
   oauth_config config = oauth_helper.get_config(2); //主键id
   if (config == null)
   {
    return content("出错了，您尚未配置微信相关的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";
   //开始发送
   return redirect(send_url); //跳转到微信自己 指定的关联登陆页面
  }
  /// <summary>
  /// 微信登录返回action
  /// </summary>
  public actionresult wechatreturnurl(string state, string code)
  {
   //取得返回参数
   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))//若返回参数中未包含code或者state没有通过验证则提示出错
   {
    return content("出错啦，state未初始化！");
   }
   //第一步：通过code来获取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("错误代码：，无法获取access token，请检查app key是否正确！");
   }
   if (dic1 == null || !dic1.containskey("openid"))
   {
    if (dic1.containskey("errmsg"))
    {
     return content("errcode：" + dic1["errcode"] + ",errmsg：" + dic1["errmsg"]);
    }
    else
    {
     return content("出错啦，无法获取用户授权openid！");
    }
   }
   access_token = dic1["access_token"].tostring();//获取access_token
   expires_in = dic1["expires_in"].tostring();//获取过期时间
   refresh_token = dic1["refresh_token"].tostring();//获取用于重新刷新access_token的凭证
   openid = dic1["openid"].tostring();//用户唯一标示openid
   //储存获取数据用到的信息
   session["oauth_name"] = "webchat";
   session["oauth_access_token"] = access_token;
   session["oauth_openid"] = openid;
   session["oauth_refresh_token"] = refresh_token;
   #region todo 将获取到的用户信息保存到数据库中
   #endregion
   //第二步：通过access token以及openid来获取用户的基本信息
   //dictionary<string, object> dic2 = weixin_helper.get_user_info(access_token,openid);
   //第三步：跳转到指定页面
   return content(wechatresultjson());
  }
  /// <summary>
  /// 微信登录返回action, 处理用户信息
  /// </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\":\"出错啦，access token已过期或不存在！\"}";
   }
   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)) //调用access_token前需判断是否过期
   {
    dictionary<string, object> dic1 = weixin_helper.get_refresh_token(oauth_refresh_token);//如果已过期则重新换取新的access_token
    if (dic1 == null || !dic1.containskey("access_token"))
    {
     return "{\"openid\":\"0\", \"msg\":\"出错啦，无法获取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\":\"出错啦，无法获取授权用户信息！\"}";
   }
   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\":\"出错啦，无法获取授权用户信息！\"}";
   }
  }
  #endregion