Question

Using the following form in a view

<% using (Ajax.BeginForm("PatientSearch", new {}, new AjaxOptions()
           {
               HttpMethod = "POST",
               UpdateTargetId = "searchResults",
               OnBegin = "BeginRequest",
               OnSuccess = "SuccessRequest",
               OnFailure = "FailRequest"
           }))
           { %>
    <%=Html.DropDownList("patientType",(SelectList)ViewData["PatientTypeList"]) %>
    <%=Html.DropDownList("edCenterID",(SelectList)ViewData["EdCenterList"]) %><br />
    <input type="submit">
<%} %>

Results in the following HTML

<select id="patientType" name="patientType">
  <option selected="selected">Referral</option>
  <option>Patient</option>
</select>
<select id="edCenterID" name="edCenterID">
  <option value="2">Barren River District Health Department</option>
  <option value="3">Madison County Health Department</option>
</select>

and I attempt to catch the values with the code in the my controller

 public ActionResult PatientSearch(string patientType, int edCenterID)        {   
   //do something with values

}

patientType is always passed as “”; however, edCenterID is posted and received just fine.

If I change this from an Ajax.BeginForm to an HTML.BeginForm, everything works perfectly.

Is the problem in my DropDownList, my controller, both?

ADDED FROM COMMENTS

@Eoin pointed out to me that my select is rendering without a value and that is probably the problem. That brings up two questions:
1. Why does it work with the a standard post, but not an Ajax post.
2. How do I get my dropdownlist to contain a value with the list is a simple string only list (no key). I am posting the code used to generate my SelectList below

ViewData["PatientTypeList"]=new SelectList(new List<string>() 
        { "Referral", "Patient"});

Answer 1

Does the patientType List have a .Value

By the looks of things, theres no value being rendered for the PatientType DDL <option>‘s so essentially every option has a value=”” so it is actually post back the correct value.

The problem is with what’s being rendered in the first place.

edit

Try

Dictionary<string, string> d = new Dictionary<string, string>();
d.Add("referral", "referral");
d.Add("patient", "patient");

ViewData["PatientTypeList"]=new SelectList(d, "Key", "Value");