The operation cannot be completed because the DbContext has been disposed
Question
I am writing a simple application in EF 4.1 which will use add, delete , edit and detail form my common data source (central server for database). In my Controller class i write:
public class RegController : Controller
{
//
// GET: /Reg/
private string CmdStr = ConfigurationManager.ConnectionStrings["MyConn"].ConnectionString;
public ActionResult Index()
{
using (var db = new RegModelContext(CmdStr))
{
return View(db.Registrant);
}
}
}
when I am executing my Application it gave me an error in index view at foreach statement:
@model IEnumerable<Registration.Models.Register>
@{
Layout = null;
}
<!DOCTYPE html>
<html>
<head>
<title>Index</title>
</head>
<body>
<p>
@Html.ActionLink("Create New", "Create")
</p>
<table>
<tr>
<th></th>
<th>
UserName
</th>
<th>
Password
</th>
<th>
Email
</th>
<th>
Address
</th>
</tr>
@foreach (var item in Model) {
<tr>
<td>
@Html.ActionLink("Edit", "Edit", new { id=item.Id }) |
@Html.ActionLink("Details", "Details", new { id=item.Id }) |
@Html.ActionLink("Delete", "Delete", new { id=item.Id })
</td>
<td>
@item.UserName
</td>
<td>
@item.Password
</td>
<td>
@item.Email
</td>
<td>
@item.Address
</td>
</tr>
}
</table>
</body>
</html>
The error is this: "The operation cannot be completed because the DbContext has been disposed."
2 answers
solution1
14 2012-08-08 07:15:52
You should use a List to pass as your model
i assume that db.Registrant return a list of users?, if so do something like this
List<Registrant> items = null;
using (var db = new RegModelContext(CmdStr))
{
items = db.Registrant.ToList();
}
return View(items);
solution2
6 2012-08-08 09:45:28
Just to comment further, you need to separate your concerns. You shouldn't use the database context like that in a controller. Rather use it through a repository or service layer.
I also had this issue when using using . I removed the using part. Modify the code below to fit in with your scenario. Assuming you are to bring back a list of users. I would have this in my repository class:
public class UserRepository : IUserRepository
{
MyDbContext dbContext = new MyDbContext();
public IEnumerable<User> GetAll()
{
return dbContext.Users;
}
}
This repository you then have injected in your controller by Autofac, Ninject, etc.
In your controller it would look something like this:
public class UserController : Controller
{
private readonly IUserRepository userRepository;
public UserController(IUserRepository userRepository)
{
this.userRepository = userRepository;
}
public ActionResult Index()
{
UserViewModel viewModel = new UserViewModel
{
Users = userRepository.GetAll()
};
}
}
And then in your view you can just loop through the users.
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