asp.net - .NET 4.5 Gridview with DropDownList in EditItemTemplate UpdateMethod -

i have gridview list of manufacturertypes related manufacturers... each manufacturertype has manufacturer (2 tables -> 2 entities). when want update item manufacturertype wan`t possible update title entity manufacturertype change (manufacturer) relation if dropdownlist selectedvalue change.

<asp:gridview id="gvmanufacturertypes" runat="server" datakeynames="manufacturertypeid"         autogeneratecolumns="false" gridlines="vertical" cssclass="gridview"         cellpadding="4" itemtype="entities.models.manufacturertype" selectmethod="getmanufacturertypeswithparams"          updatemethod="updateitem" deletemethod="deleteitem"         allowpaging="true" allowsorting="true" pagesize="20" pagersettings-firstpagetext="prvi"         pagersettings-lastpagetext="zadnji" pagersettings-mode="numericfirstlast"         oncallingdatamethods="gvmanufacturertypes_callingdatamethods">         <columns>             <asp:templatefield headertext="proizvajalec">                 <itemtemplate>                     <asp:label id="lblmanufacturer" text='<%# item.manufacturer.title %>' runat="server" />                 </itemtemplate>                 <edititemtemplate>                     <asp:dropdownlist id="ddlmanufacturers" runat="server" itemtype="entities.models.manufacturer" selectmethod="getmanufacturers" selectedvalue='<%# item.manufacturer.manufacturerid %>'                         datatextfield="title" datavaluefield="manufacturerid" oncallingdatamethods="ddlmanufacturers_callingdatamethods">                                                 </asp:dropdownlist>                 </edititemtemplate>             </asp:templatefield>             <asp:dynamicfield datafield="title" />             <asp:commandfield showeditbutton="true" edittext="uredi" updatetext="shrani" canceltext="prekliči" itemstyle-width="80" />             <asp:commandfield showdeletebutton="true" deletetext="izbriši" itemstyle-width="80" />         </columns>         <pagerstyle cssclass="gridview_pager" />     </asp:gridview> 

it generates me updateitem method , change load item , save changes sections below:

// id parameter name should match datakeynames value set on control     public void updateitem(int manufacturertypeid, modelmethodcontext context)     {         manufacturertype item = null;          // load item here         item = _manufacturertyperepository.getallwithrelations(m => m.manufacturer)             .where(x => x.manufacturertypeid == manufacturertypeid).singleordefault();          if (item == null)         {             // item wasn't found             context.modelstate.addmodelerror("", string.format("proizvajalec z idjem {0} ne obstaja.", manufacturertypeid));             return;         }         context.tryupdatemodel(item);         if (context.modelstate.isvalid)         {             // save changes here             _manufacturertyperepository.save();         }     } 

i call include manufacturertype entity include("manufacturer") ... current manufacturertype, , tryupdatemodel method change title of manufacturertype (if change on edit in gridview), manufacturer stays same... have try put dropdownlist control-parameter updatemethod like

public void updateitem(int manufacturertypeid, [control] manufacturerid, modelmethodcontext context) 

but null... don`t know how transfare value dropdownlist updateitem method (updateitem not in codebehind of manufacturertypes.aspx in busines logic layer) manufacturertypebl.cs...

i didn`t find solution use new features itemtype in gridview , select method , selectmethod in dropdownlist etc...

maybe need change updateitem method old fasioned way onupdating method , read values dropdown , lather call busines logic layer params?

edit - > add model classes (manufacturer, manufacturertype)

public class manufacturer {     [key, foreignkey("manufacturertype")]     public int manufacturerid { get; set; }      [stringlength(255)]     public string title { get; set; }      public manufacturertype manufacturertype { get; set; } }  public class manufacturertype {     [key]     public int manufacturertypeid { get; set; }              [stringlength(50)]     public string title { get; set; }      public manufacturer manufacturer { get; set; }  } 

from can understand,

in edititemtempalte set selectedvalue='<%# bind("manufacturerid")%>'. i.e. property name manufacturerid in manufacturertype entity.

also, should not required fetch relation (in select query). if fetch manufacturertype item, , use correct property name in edittemplate controls, should work fine.

if can post model classes (manufacturer , manufacturertype) more helpful understand issue.