public static string GetWxTokenId()
    {
      string token = "";
      string url = string.Format("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={0}&secret={1}", appid, secret);
      //向上面的地址发起httpget请求
      //这里是封装的一个http请求的类
      string content = HttpHelper.HttpGet(url);
      if (!string.IsNullOrEmpty(content))
      {
        var obj = JsonConvert.DeserializeObject<TokenResult>(content);
        if (!obj.errcode.HasValue)
        {
          token = obj.access_token;
        }
      }
      return token;
    }

private class TokenResult
    {
      public string access_token { get; set; }
      public string expires_in { get; set; }
      public int? errcode { get; set; }
      public string errmsg { get; set; }
    }

/// <summary>
 /// 获取ticket
 /// </summary>
 /// <param name="token">获取到的tokenid</param>
 /// <returns>strticket</returns>
 public static string GetTicket(string token)
 {
      string getticketurl = string.Format("https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token={0}&type=jsapi", token);
      string content = HttpHelper.HttpGet(getticketurl);
      JsApiTicket obj = JsonConvert.DeserializeObject<JsApiTicket>(content);
      return obj.ticket;
 }

//生成签名的随机串
string noncestr = Guid.NewGuid().ToString().Replace("-", "");

TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);
string timestamp = Convert.ToInt64(ts.TotalSeconds).ToString();

string signature = MakeSha1Sign(string.Format("jsapi_ticket={0}&noncestr={1}×tamp={2}&url={3}", jsapi_ticket, noncestr, timestamp, url));
/// <summary>
    /// SDK生成签名
    /// 注意：需要引用System.Security.dll
    /// </summary>
    /// <param name="str"></param>
    /// <returns>str签名</returns>
    public static string MakeSha1Sign(string str)
    {
      byte[] StrRes = Encoding.Default.GetBytes(str);
      HashAlgorithm iSHA = new SHA1CryptoServiceProvider();
      StrRes = iSHA.ComputeHash(StrRes);
      StringBuilder EnText = new StringBuilder();
      foreach (byte iByte in StrRes)
      {
        EnText.AppendFormat("{0:x2}", iByte);
      }
      return EnText.ToString();
    }

/// <summary>
    /// 获取调用微信接口用的SDKConfig
    /// </summary>
    /// <param name="url"></param>
    /// <returns>SDKConfig整个对象</returns>
    public static JsApiConfig GetJsSdkConfig(string url)
    {
      //获取tokenid
      string access_token = GetWxTokenId();
      //获取ticket
      string jsapi_ticket = GetTicket(access_token);
      //生成签名的随机串
      string noncestr = Guid.NewGuid().ToString().Replace("-", "");
      //生成签名的时间戳
      TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0);
      string timestamp = Convert.ToInt64(ts.TotalSeconds).ToString();
      //签名
      string signature = MakeSha1Sign(string.Format("jsapi_ticket={0}&noncestr={1}×tamp={2}&url={3}", jsapi_ticket, noncestr, timestamp, url));

      JsApiConfig config = new JsApiConfig()
      {
        appId = appid,
        debug = false,
        nonceStr = noncestr,
        timestamp = timestamp,
        signature = signature,
        ticket = jsapi_ticket,
        //需要使用的JS接口列表
        jsApiList = new string[] { "chooseImage", "previewImage", "uploadImage", "downloadImage" }

      };
      return config;


    }

$.post('/WapCardInfo/GetSDKConfig', { url: location.href.split('#')[0] }, function (data) {
  var configObj = data;

      wx.config({
        debug: false, // 开启调试模式,调用的所有api的返回值会在客户端alert出来，若要查看传入的参数，可以在pc端打开，参数信息会通过log打出，仅在pc端时才会打印。
        appId: configObj.appId, // 必填，公众号的唯一标识
        timestamp: configObj.timestamp, // 必填，生成签名的时间戳
        nonceStr: configObj.nonceStr, // 必填，生成签名的随机串
        signature: configObj.signature, // 必填，签名，见附录1
        jsApiList: [
                'checkJsApi',
                'onMenuShareTimeline',
                'onMenuShareAppMessage',
                'onMenuShareQQ',
                'onMenuShareWeibo',
                'onMenuShareQZone'
        ] // 必填，需要使用的JS接口列表，所有JS接口列表见附录2
      });
});

[HttpPost]
    public JsonResult GetSDKConfig(string url)
    {
      try
      {
  //这里就是调用上面封装的方法
        JsSdkApi.jsapiConfig model = JsSdkApi.GetJsSdkConfig(url);
        return Json(model);
      }
      catch (Exception ex)
      {
        LogHelper.Error("获取wxconfig出现异常：" + ex.Message.Replace("'", "\""));
        return Json(new JsSdkApi.jsapiConfig());
      }
    }