pagedlist - ASP.NET MVC Html.PagedListPager Not Working -

mycontroller:

    public actionresult index(string searchstring, int? page)     {         var query = _mytable in _mydatacontext.mytables select _mytable;          int pagesize = 10;              // contain 10 products max because of pagesize         int pagenumber = (page ?? 1);   // if no page specified in querystring, default first page (1)          pagedlist.pagedlist<mytables> models = new pagedlist.pagedlist<anlagen>(query, pagenumber, pagesize);          return view(models);     } 

myview, last line:

@html.pagedlistpager(model, page => url.action("index", new { viewbag.searchstring, page})) 

i don't know why, pagination is: «|‹|1|›|»

calling page "?searchstring=hello&page=2" works results, same pagination: «|‹|1|›|»

here search form:

<form action="@url.action("index", "anlagen")" method="get" role="search" class="navbar-form-custom">     <div class="form-group input-group">         <input type="text" class="form-control" placeholder="suchen..." id="searchstring" name="searchstring" value="@viewbag.searchstring" />     </div> </form> 

just copy working project, in new project doesn't work :(

i believe have order elements pagedlist work properly. adjust linq order collection value, such name if exists:

var query = _mytable in _mydatacontext.mytables orderby _mytable.name select _mytable;