JS FormData Post WebApi

        var dataObj = {
            "cateId": 7,
            "pageCount":10,
            "pageNum":0,
            "S_CaoZuoR":"sclgs",
            "B_IsShow":1
        };
        postFormData(dataObj);    



    function postFormData(dataObj) {

        var formData = new FormData();
        for (var key in dataObj) {
            formData.append(key, dataObj[key]);
        }

        $.ajax({
            type: "POST",
            url: url,
            cache: false,
            processData: false,
            contentType: false,
            data: formData,
            success: function (data) {
                return data;
            },
            error: function (xhr, state, err) {
                alert(JSON.stringify(err));
            }
        });

    }

 [HttpPost]
        [Route("content/SelectPageByAdmin3")]
        public IEnumerable<PW_Content> SelectPageByAdmin3()
        {
            int cateId = Convert.ToInt32(HttpContext.Current.Request.Params["cateId"]);
            int pageCount = Convert.ToInt32(HttpContext.Current.Request.Params["pageCount"]);
            int pageNum = Convert.ToInt32(HttpContext.Current.Request.Params["pageNum"]);
            string S_CaoZuoR = HttpContext.Current.Request.Params["S_CaoZuoR"].ToString();
            int B_IsShow = Convert.ToInt32(HttpContext.Current.Request.Params["B_IsShow"].ToString());

            return Service.SelectPageByAdmin2(cateId, pageCount, pageNum, S_CaoZuoR, B_IsShow);
        }