How to keep dropdownlist selected value after postback

Question

In asp.net mvc3 how to keep dropdown list selected item after postback.

Answer 1

If you are building the drop down list data source in the controller Action Method you can send the selected value to it

Controller:

 public ActionResult Index( int serviceid=0)
            {


             // build the drop down list data source
                List services = db.Service.ToList();
                services.Insert(0, new Service() { ServiceID = 0, ServiceName = "All" });
               // serviceid is the selected value you want to maintain
                ViewBag.ServicesList = new SelectList(services, "ServiceID", "ServiceName",serviceid);

               if (serviceid == 0)
                {
                    //do something
                }
                else
                {
                     // do another thing

                }
                return View();
           }

View:

 //ServiceList is coming from ViewBag
@Html.DropDownList("ServicesList", null, htmlAttributes: new { @class = "form-control" })