checkbox does not retain its state - asp.net-mvc-3

Question

I am a beginner in asp mvc 3, and i develop an application ,
I first want to describe my application
so i have in my database , a table account and a table role and the relation ship between account and role is many to many, so i have a association table account_role,
i work with Entity Framework database first and i generate my POCO with EF DbContext Generator,
i want ann edit Account page dispay a chekbox of Roles
this is my code
Controller Account
public ActionResult Edit(int id)
{
accounts accounts = db.accounts
.Include(i => i.roles_accounts)
.Where(i => i.id_account == id)
.Single();
PopulateAssignedRoleData(accounts);
return View(accounts);
}
// populate Assigned RoleDATA pour afficher les checkbox
private void PopulateAssignedRoleData(accounts account)
{
//Get all role
var allRole =db.roles;
//For each role, the code checks if the role exists in the property of accountRole
// To create effective search when checking if a role is assigned to the account,
// assigned roles in are put into a collection HashSet
var accountRoles = new HashSet<int>(account.roles_accounts.Select(r => r.id_account_role));
var viewModel = new List<AssignedRoleData>();
// Property Assigned role of which is allocated account is set to true.
//The view will use this property to determine
//what check boxes to be displayed as selected.
//Finally, the list is passed to the view in a ViewBag
foreach (var role in allRole)
{
viewModel.Add(new AssignedRoleData
{
RoleId = role.id_role,
Name = role.name,
Assigned = accountRoles.Contains(role.id_role)
});
}
ViewBag.roles = viewModel;
}
//
// POST: /Account/Edit/5
[HttpPost]
public ActionResult Edit(int id, FormCollection formCollection, string [] selectedRoles)
{
var accountsToUpdate = db.accounts
.Include(i => i.roles_accounts)
.Where(i => i.id_account == id)
.Single();
if (TryUpdateModel(accountsToUpdate, "", null, new string[] { "roles_accounts" }))
{
try
{
if (String.IsNullOrWhiteSpace(accountsToUpdate.login))
{
accountsToUpdate.roles_accounts = null;
}
UpdateAccountRole(selectedRoles, accountsToUpdate);
db.Entry(accountsToUpdate).State = EntityState.Modified;
db.SaveChanges();
return RedirectToAction("Index");
}
catch (DataException)
{
ModelState.AddModelError("", "Unable to save change");
}
}
PopulateAssignedRoleData(accountsToUpdate);
return View(accountsToUpdate);
}
// update AccountRole (liste of checkbox)
private void UpdateAccountRole(string[] selectedRoles, accounts accountToUpdate)
{
if (selectedRoles == null)
{
accountToUpdate.roles_accounts=new List<roles_accounts>();
return;
}
var selectedRolesHS = new HashSet<string>(selectedRoles);
var accountsRoles = new HashSet<int>
(accountToUpdate.roles_accounts.Select(r => r.id_account_role));
foreach(var role in db.roles_accounts)
{
if( selectedRolesHS.Contains(role.id_account_role.ToString()))
{
if(!accountsRoles.Contains(role.id_account_role))
{
accountToUpdate.roles_accounts.Add(role);
}
}
else
{
if (accountsRoles.Contains(role.id_account_role))
{
accountToUpdate.roles_accounts.Remove(role);
}
}
}
}
And i create a folder nammed ViewModels, and in this folder i create a classe AssignedRoleData To provide data to the view for the list of check boxes,
this is the AssignedRoleData
public class AssignedRoleData
{
public int RoleId { get; set; }
public string Name { get; set; }
public bool Assigned { get; set; }
and in the Edit.schtml
i put this code
<div class="editor-field">
<table>
<tr>
#{
int cnt = 0;
List<App_ERP1.ViewModels.AssignedRoleData> roles=ViewBag.roles;
foreach (var role in roles) {
if (cnt++ % 3 == 0) {
#: </tr> <tr>
}
#: <td>
<input type="checkbox"
name="selectedRoles"
value="#role.RoleId"
#(Html.Raw(role.Assigned ? "checked=\"checked\"" : "")) />
#role.RoleId #: #role.Name
#:</td>
}
#: </tr>
}
}
}
My Problem is the checkbox does not retain its state and also each time when I click the save button it removes the added roles (choose)
thanks to help me

Answer 1

you need to use a "for" instead of the "foreach" on the view and your attribute "name" probably needs to be something like name="selectedRoles[i]" . Tip: Don't access the database directly on the controller. Create a middle layer where you have the class AccountRoleService and here put the logic and then create another layer for accessing the database called repository (e.g AccountRoleRepository) where you actually do your LINQ to SQL stuff. If you want to reuse methods will be much easier. So controllers do little and call service classes. Service classes do logic and call repository classes to access the database. So if you want to unit test the services you will be on the right path.

Answer 2

for (i = 0; i< roles.Count, i++) {
if (cnt++ % 3 == 0) {
#: </tr> <tr>
}
#: <td>
<input type="checkbox"
name="selectedRoles[" + i + "]"
value="#role.RoleId"
#(Html.Raw(role.Assigned ? "checked=\"checked\"" : "")) />
#role.RoleId #: #role.Name
#:</td>
}
#: </tr>