asp.net mvc - HttpPost Action get empty Model on button Click -

scenario

i have master/detail page master data on top , detail data loop in table format.
i want id when user clicks on button.

problem

httppost action in called empty model. want saleid hiddenfield, not fields required

my models

// sales master model public class sales {     [required]     [display(name = "sale_id")]     public long saleid { get; set; }     [required]     [display(name = "orderdate")]     public datetime orderdate { get; set; }     [required]     [display(name = "name")]     public string name { get; set; } } // detail model public class salesdetail {     [required]     [display(name = "sale_id")]     public long saleid { get; set; }      [required]     [display(name = "pkg_dur")]     public int pkgdur { get; set; }      [required]     [display(name = "m_name")]     public string mname { get; set; }      [display(name = "price")]     public decimal price { get; set; } } // used display data in view  public class salesmd {     public sales sale = new sales();     public list<salesdetail> detail = new list<salesdetail>(); } 

view is

   @model namespace.models.salesmd    //for showing master data        @html.hiddenfor(m => m.sale.saleid)        @html.displayfor(m => m.sale.name)        @html.displayfor(m => m.sale.orderdate)    // showing detail data in table form   @foreach (var item in model.detail)    {       @html.displayfor(modelitem => item.mname)       @html.displayfor(modelitem => item.pkgdur) month(s)       @html.displayfor(modelitem => item.price)    } 

controller

    public actionresult salesdetail(models.salesmd md) 

(here md getting values 0s , null)
remember: want saleid hiddenfield trying saleid md.sale.saleid zero

finally rendered html of hidden field. have value

   <input data-val="true" data-val-number="the field sale_id must number."       data-val-required="the sale_id field required." id="sale_saleid"        name="sale.saleid" type="hidden" value="2"> 

when using

   [httppost]    public actionresult salesdetail(long saleid)  

it generating exception

the parameters dictionary contains null entry parameter 'saleid' of non-nullable type 'system.int64' method 'system.web.mvc.actionresult salesdetail(int64)' in 'mak_erp.controllers.makadmincontroller'. optional parameter must reference type, nullable type, or declared optional parameter. parameter name: parameters

solution

finally solved using html.hiddenfor instead of html.displayfor

html.displayfor, displaying model properties in view. doesn't render input in view. so, obviously, model null, because there's no data collected in view , submitted controller.

you need use html.editorfor instead.

if need post hidden input controller, why trying bind posted data viewmodel? change action this:

public actionresult salesdetail(long saleid) { }