How can I fix this error in asp.net mvc -

inside index.cshtml, have dropdownlist populated data. on selection of dropdownlist item, loading partial views using ajax. these partial views forms, when filled, data inserted database. after insertion, want go index.cshtml has populated dropdownlist initially, doesn't work , gives error:

an exception of type 'system.invalidoperationexception' occurred in system.web.mvc.dll not handled in user code additional information: there no viewdata item of type 'ienumerable' has key 'templatescategory'.

here controller ----

 public class templatecontroller : controller     {         pulsecontext db = new pulsecontext();         public actionresult index()         {             viewbag.templatescategory = new selectlist(db.templates, "id", "templatename");             return view();         }         [httpget]         public partialviewresult clothing()         {             return partialview("_clothingtemplate");         }         [httppost]         public actionresult clothing(templateclothing tc)         {             db.templateclothings.add(tc);             db.savechanges();             return view("index");         } 

here view -----

    @model pulse.models.templates      @{         viewbag.title = "index";     }     <div class="container">         <script src="~/scripts/jquery-2.2.3.min.js"></script>         <script src="~/scripts/bootstrap.min.js"></script>         <h2>select template</h2>         @html.dropdownlist("templatescategory")         <script type="text/javascript">         $(document).ready(function () {             $("#templatescategory").change(function () {                 var choice = this.value;                 if (choice === "1") {                     $.ajax({                         url: '/template/footwear',                         contenttype: 'application/html;charset=utf-8',                         type: 'get',                         datatype:'html'                     })                     .success(function(result){                     $('#templatecontainer').html(result)                 })                 }                 else if (choice === "2") {                     $.ajax({                         url: '/template/accessory',                         contenttype: 'application/html;charset=utf-8',                         type: 'get',                         datatype: 'html'                     })                     .success(function (result) {                         $('#templatecontainer').html(result)                     })                 }                 else if (choice === "3") {                     $.ajax({                         url: '/template/clothing',                         contenttype: 'application/html;charset=utf-8',                         type: 'get',                         datatype: 'html'                     })                     .success(function (result) {                         $('#templatecontainer').html(result)                     })                 }             });         });         </script>         <div id="templatecontainer"></div>     </div> 

here model --

namespace pulse.models {     using system;     using system.collections.generic;      public partial class templates     {         public templates()         {             this.templateaccessoriestbls = new hashset<templateaccessories>();             this.templateclothingtbls = new hashset<templateclothing>();             this.templatefootweartbls = new hashset<templatefootwear>();         }          public int id { get; set; }         public string templatename { get; set; }          public virtual icollection<templateaccessories> templateaccessoriestbls { get; set; }         public virtual icollection<templateclothing> templateclothingtbls { get; set; }         public virtual icollection<templatefootwear> templatefootweartbls { get; set; }     } } 

please me how can fix error , also, how redirect index page populated dropdown.

in case done call index method before rendering view want

return redirecttoaction("index");  

instead of : return view("index");

so clothing should below

    [httppost]     public actionresult clothing(templateclothing tc)     {         db.templateclothings.add(tc);         db.savechanges();         return redirecttoaction("index");     } 

this recall index method , render view want