asp.net mvc - submit a list become null in the post + MVC -

i have viewmodel:

public class registrationviewmodel {     public string country { get; set; }     public configurationparamvalue countryparam { get; set; }     public string civility { get; set; }     public configurationparamvalue civilityparam { get; set; }     [firstnamevalidator(category = "registration", islocal = false )]     public string firstname { get; set; }     public configurationparamvalue firstnameparam { get; set; }     [lastnamevalidator(category = "registration", islocal = false)]     public string lastname { get; set; }     public list<int> days { get; set; }     public int selectedday{ get; set; }     public list<month> months { get; set; }     public month selectedmonth { get; set; }     public list<int> years { get; set; }     public int selectedyear { get; set; }     public datetime birthdate { get; set; } } 

i create view viewmodel :

@model registration.front.web.models.registrationviewmodel  @{     viewbag.title = "index";     layout = "~/views/shared/_layout.cshtml"; }  <h2>index</h2>  @using (html.beginform()) {     @html.antiforgerytoken()     @html.validationsummary(true)      <fieldset>         <legend>registrationviewmodel</legend>          <div class="editor-label">             @html.labelfor(model => model.country)         </div>         <div class="editor-field">             @html.editorfor(model => model.country)             @html.validationmessagefor(model => model.country)         </div>          <div class="editor-label">             @html.labelfor(model => model.civility)         </div>         <div class="editor-field">             @html.editorfor(model => model.civility)             @html.validationmessagefor(model => model.civility)         </div>          <div class="editor-label">             @html.labelfor(model => model.firstname)         </div>         <div class="editor-field">             @html.editorfor(model => model.firstname)             @html.validationmessagefor(model => model.firstname)         </div>          <div class="editor-label">             @html.labelfor(model => model.lastname)         </div>         <div class="editor-field">             @html.editorfor(model => model.lastname)             @html.validationmessagefor(model => model.lastname)         </div>          <div class="editor-label">             @html.labelfor(model => model.birthdate)         </div>         <div class="editor-field">             @html.dropdownlistfor(model => model.selectedday, new selectlist(model.days))             @html.validationmessagefor(model => model.birthdate)         </div>          <div class="editor-label">             @html.labelfor(model => model.occupation)         </div>         <div class="editor-field">             @html.editorfor(model => model.occupation)             @html.validationmessagefor(model => model.occupation)         </div>          <div class="editor-label">             @html.labelfor(model => model.zipcode)         </div>         <div class="editor-field">             @html.editorfor(model => model.zipcode)             @html.validationmessagefor(model => model.zipcode)         </div>          <div class="editor-label">             @html.labelfor(model => model.email)         </div>         <div class="editor-field">             @html.editorfor(model => model.email)             @html.validationmessagefor(model => model.email)         </div>          <div class="editor-label">             @html.labelfor(model => model.password)         </div>         <div class="editor-field">             @html.editorfor(model => model.password)             @html.validationmessagefor(model => model.password)         </div>          <div class="editor-label">             @html.labelfor(model => model.cgv)         </div>         <div class="editor-field">             @html.editorfor(model => model.cgv)             @html.validationmessagefor(model => model.cgv)         </div>          <div class="editor-label">             @html.labelfor(model => model.optin)         </div>         <div class="editor-field">             @html.editorfor(model => model.optin)             @html.validationmessagefor(model => model.optin)         </div>          <div class="editor-label">             @html.labelfor(model => model.cnil)         </div>         <div class="editor-field">             @html.editorfor(model => model.cnil)             @html.validationmessagefor(model => model.cnil)         </div>          <p>             <input type="submit" value="create" />         </p>     </fieldset> }  <div>     @html.actionlink("back list", "index") </div> 

this contoller:

public actionresult index()         {         list<int> listdays = new list<int>(){1, 2, 3};         return view(new registrationviewmodel() { days=listdays });         }  [httppost] public actionresult index( registrationviewmodel rvm)        {        if (modelstate.isvalid)           { return redirecttoaction("welcome"); }         return view(rvm);        }  public actionresult welcome()       {       return view();       } 

my problem in post, property days of viewmodel null!!!!! how can correct this?

in view not rendering days inside form

render hidden fields inside form name="days" like

foreach(var day in @model.days) { <input type="hidden" name="days" /> }

copy above code , paste after <div class="editor-field"> @html.editorfor(model => model.cnil) @html.validationmessagefor(model => model.cnil) </div>

now,when submit, days values submitted post method , values in days list.