How to append string as anchor tag link in Web Method using C# in ASP.Net

http://www.aspsnippets.com/Articles/Implement-Infinite-Scroll-Endless-Scroll-in-ASPNet-using-jQuery-AJAX.aspx

https://www.codeproject.com/Articles/426116/How-to-implement-Infinite-Scroll-in-web-applicatio

i study those example and work very well..only id like to implement

link for classic details page in an e-commerce site

[System.Web.Services.WebMethod]
public static string LoadProduct(int Skip, int Take)
{
    System.Threading.Thread.Sleep(1000);
    StringBuilder GetProduct = new StringBuilder();

    String vLinea = (String)HttpContext.Current.Session["LINEA"];

    MyDataBaseEntities db = new MyDataBaseEntities();
    var prod = (from a in db.Tabella
                where a.linea == vLinea.ToString()
                orderby a.cod_numerico descending
                select a).Skip(Skip).Take(Take);

    foreach (var a in prod)
    {
        var Codart = a.Codart;
        var Prezz3 = a.Prezz3;
        var pathimg = a.pathimg;

        GetProduct.Append("<div class=\"col-md-4\">");
        GetProduct.Append("<div class=\"col-md-6 text-left\">");

        GetProduct.AppendFormat("<span class=\"codart\">{0}</span>", Codart);

        GetProduct.Append("</div> ");
        GetProduct.Append("<div class=\"col-md-6 text-right\" style=\"color:gray;font-size:large;\">");
        GetProduct.AppendFormat(string.Format("{0:c}",  Prezz3));
        GetProduct.Append("</div> ");
       **GetProduct.AppendFormat(string.Format("<a href='<%#: GetRouteUrl(\"ProductByCodePromo\", new {ProductCodePromo = Item.{0} }) %>'>", Codart));**
        GetProduct.AppendFormat(string.Format("<img src='{0}' class='img-responsive MyImage' alt='{1}'/>", pathimg, Codart));
        GetProduct.Append("</a>");
        GetProduct.Append("</div> ");
    }
    return GetProduct.ToString();
}  how can i write the link???