public void getAda()
    {
        //获取openid
        // //// 链接地址
        ////https://open.weixin.qq.com/connect/oauth2/authorize?appid=11111111111111111111111111111&redirect_uri=22222222222222222&response_type=code&scope=SCOPE&state=STATE#wechat_redirect 
        //int id = Convert.ToInt32(Request.QueryString["ID"]);
        string code = Request["code"].ToString();
        string html = string.Empty;
        string url = "https://api.weixin.qq.com/sns/oauth2/access_token?appid=11111111111111111111111111111111111&secret=2222222222222222222222228&code=" + code + "&grant_type=authorization_code";
        HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
        request.Method = "GET";
        HttpWebResponse response = request.GetResponse() as HttpWebResponse;
        Stream ioStream = response.GetResponseStream();
        StreamReader sr = new StreamReader(ioStream, Encoding.UTF8);
        html = sr.ReadToEnd();
        sr.Close();
        ioStream.Close();
        response.Close();

        string key = "\"openid\":\"";
        int startIndex = html.IndexOf(key);
        if (startIndex != -1)
        {
            int endIndex = html.IndexOf("\",", startIndex);
            string openid = html.Substring(startIndex + key.Length, endIndex - startIndex - key.Length);
            //MyOpenId.Value=openid;
            Response.Write(openid);
                       
        }
        else
        {
            Response.Write("找不到OpenidID");
        }
    }