Problem

error cannot simplicity convert string to system.collection.generic.ienumerable on view of index

Details

I need to display every department and his employees following to it in tree view using jtree i downloaded from nugget in mvc 5 visual studio 2015 . as department parent and children employee

Sales(parent)
michel(children)
divid(children)
my database data as following
  1. SELECT        dbo.Departments.DepartmentName, dbo.Employee.EmployeeName, dbo.Employee.DepartmentID  
  2. FROM            dbo.Employee INNER JOIN  
  3.                          dbo.Departments ON dbo.Employee.DepartmentID = dbo.Departments.DepartmentID  
 
 

and treeviewhelper class has following function for children

  1. public TreeView Children(Func> selector)  
  2.        {  
  3.            //  if (selector == null) //throw new ArgumentNullException("selector");    
  4.            _childrenProperty = selector;  
  5.            return this;  
  6.        }  
 

my employee controller as following

  1. public class EmployeeController : Controller  
  2.     {  
  3.         // GET: Employee  
  4.         HRSystem hr = new HRSystem();  
  5.         public ActionResult Index()  
  6.         {  
  7.             IEnumerable catgory1 = hr.Employees.Where(x => !x.DepartmentID.HasValue).ToList();  
  8.             return View(catgory1);  
  9.         }  
  10.     }  
 

my error show on view of index as following

 
  1. @model IEnumerable  
  2. @using System.Web.UI.WebControls  
  3. @using EmployeeSystem.Models;  
  4.   

  5. TreeView

      
  6. "~/Content/jsTree/themes/default/style.min.css" rel="stylesheet" />  
  7. class="form-body">  
  8.     "jstree">  
  9.         @(Html.TreeView(Model)  
  10.                               .EmptyContent("root")  
  11.                               .Children(m=>m.EmployeeName)  
  12.                               .HtmlAttributes(new { id = "tree" })  
  13.                           .ChildrenHtmlAttributes(new { @class = "subItem" })  
  14.                               .ItemText(m => m.EmployeeName)  
  15.                               .ItemTemplate(  
  16.         @  
  17.             "@item.EmployeeName" desc="@item.EmployeeName">@item.EmployeeName  
  18.         )  
  19.         )  
  20.     
  
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