var responseString = oSession.GetResponseBodyAsString();
var postdat = responseString ;
var requestString = oSession.GetRequestBodyAsString ();
//var str='{}';//构造自己的JsON http请求的信息及返回的结果
var data = Fiddler.WebFormats.JSON.JsonDecode(requestString);
var secondCategoryId =data.JSONObject["secondCategoryId"];