ASP.NET MVC 4 Razor编辑所选列表项

Question

I am displaying list of my model objects in a Listbox in my view.
When I select a particular item in the Listbox and click edit, I would like to edit that particular Model object.
View :

    @Html.ListBox("Employees", (IEnumerable<SelectListItem>)ViewBag.EmployeesList )
    @Html.ActionLink("Edit", "Edit", new { id=????})

I need to get the list box selected item id at runtime to provide it in the actionlink.

Controller :

    public ActionResult Index()
    {
      var Employees= db.Employees;
      ViewBag.EmployeesList = new SelectList(Employees, "EmployeeID", "EmployeeName");
      return View();
    }

    public ActionResult Edit(int id)
    {
      Employee employee = db.Employees.Find(id);
      return View();
    }

    [HttpPost]
    public ActionResult Edit(Employee emp)
    {
        try
        {
            // TODO: Add update logic here
            if (ModelState.IsValid)
               db.Entry(emp).State = EntityState.Modified;             
             db.SaveChanges();                   
             return RedirectToAction("Index");
        }
        catch
        {
            return View(emp);
        }
    }

I am not able to get the right URL like:

http://127.0.0.1:81/Employee/Edit/1

Answer 1

The listbox can have multiple selected items so you need to create two lists in a model.

Something like this:

public class EmployeeViewModel
{
    public string[] SelectedEmployeesList { get; set; }
    public IEnumerable<SelectListItem> Items { get; set; }
}

The first for the selected items and the second for the items in the list.

In your Edit get method you need to set the model list items and return it to the view ie

public ActionResult Edit(int id)
{
  var model = new EmployeeViewModel();
  Employee employee = db.Employees.Find(id);
  var model = new EmployeeViewModel
    {
        Items = new SelectList(new[]
        {
            new SelectListItem { Value = "1", Text = "Employee 1" },
            new SelectListItem { Value = "2", Text = "Employee 2" },
        }, "Value", "Text")
    };
  model.SelectedEmployeeList = new [] {1};
  return View(model);
}

In your view it will be something like this:

Html.ListBoxFor(model => model.SelectedEmployeeList, Model.Items)

Sorry I have not had time to check this code for errors, hope it works for you.