Jquery结合Ajax和Web服务使用三层架构实现无刷新分页

在Web服务里代码

/// <summary>
    /// WebService1 的摘要说明
    /// </summary>
    [WebService(Namespace = "https://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]
    // 若要允许使用 ASP.NET AJAX 从脚本中调用此 Web 服务，请取消对下行的注释。
    [System.Web.Script.Services.ScriptService]
    public class WebService1 : System.Web.Services.WebService
    {

        [WebMethod]
        public string HelloWorld()
        {
            return "Hello World";
        }
        [WebMethod]
        public List<Model.T_Student> GetListAjax(int pageindex,int pagesize) {
            BLL.T_Student bll = new BLL.T_Student();
            int count= bll.GetRecordCount("");
            DataTable dt = bll.GetListDataTable(pageindex, pagesize);
            List<Model.T_Student> li = new List<Model.T_Student>();
            string name = "";
            int age;
            string gender = "";
            foreach (DataRow row in dt.Rows)
            {
                name = row["sName"].ToString();
                age =Convert.ToInt32(row["sAge"]);
                gender = row["sGender"].ToString();
                Model.T_Student model = new Model.T_Student();
                model.sName = name;
                model.sAge = age;
                model.sGender = gender;
                li.Add(model);
            }
            return li;
        }
        [WebMethod]
        public int GetLastPageindex(int pagesize)
        {
            BLL.T_Student bnews = new BLL.T_Student();
            int totalcount = bnews.GetRecordCount("");
            if (totalcount % pagesize == 0)
            {
                return totalcount / pagesize;
            }
            else
            {
                return totalcount / pagesize + 1;
            }
        }
    }/// <summary>
    /// WebService1 的