ASP.NET MVC 3 Dropdownlist of Users

问题

In my application I have associated my UserId to a table in my database. I need that when I create a new item I can choose the user name from a dropdownlist. And 'possible to do this with the element viewbag?

@Html.EditorFor(model => model.UserId)

I use default membership provider so I can't use Entity Framework for this problem

EDIT

EDIT 2

This is my action create:

[HttpPost]
public ActionResult Create(Employe employe)
{
        var users = Roles.GetUsersInRole("Admin");
        SelectList list = new SelectList(users);
        ViewBag.Users = list;
        if (ModelState.IsValid)
        {
            **employe.EmployeID = users;**
            db.Employes.Add(employe);
            db.SaveChanges();
}

This does not work. The error is:

Cannot implicitly convert type 'string[]' to 'string'

My model for Employee

public class Employee
{
        [Key]
        public int EmployeID { get; set; }

        public Guid UserId { get; set; }

        public string Name { get; set; }

        [ForeignKey("UserId")]
        public virtual MembershipUser User
        {
            get
            {
                return Membership.GetUser(this.Name); //Changed this to Name 
            }
        }

    }
}

View:

@Html.DropDownList("Users", ViewBag.Users as SelectList);

My result in UserId field isn't a UserId but this 000000-000000-0000000-00000

回答1:

How to set a list of users as a SelectItem in the ViewBack Yes, you should be able to do this by passing your collection to the ViewBag and then create you dropdown from it:

In your controller

        var users = Roles.GetUsersInRole("Admin");
        SelectList list = new SelectList(users);
        ViewBag.Users = list;

In your View (If you're using Razor)

@Html.DropDownList("Users", ViewBag.Users as SelectList);

Read more about SelectListItem here:

• http://msdn.microsoft.com/en-us/library/system.web.mvc.selectlistitem.aspx

Also check out:

• How can I get this ASP.NET MVC SelectList to work?
• Problem with ASP.Net MVC SelectLIst and List<SelectListItems>

Question changed to something more. Here is my idea to solve the issue:

Controller:

public ActionResult Mirko() {
    List<SelectListItem> items = new List<SelectListItem>();    
    foreach (string userName in Roles.GetUsersInRole("Admin")) {
        var user = Membership.GetUser(userName);
        SelectListItem li = new SelectListItem {
            Value = user.ProviderUserKey.ToString(),
            Text = user.UserName,
        };
        items.Add(li);
    }
    items.Add(new SelectListItem { Text = "Please Select...", Value = "na" , Selected = true});
    ViewBag.Users = items;
    return View();                
}

[HttpPost]
public ActionResult Mirko(Employee employee) {
    if(IsValideEmployee(employee)) {
        /*Only used to show that user was retrieved*/
        TempData["message"] = "Saved Employee";
        TempData["user"] = employee.User;

       /* employeeRepository.Save(employee) */

        /* Redirect to where you want to go */
        return RedirectToAction("Mirko", "Home");
    }
    return View(employee);
}

private bool IsValideEmployee(Employee emp) {
    if (emp.Name == "na")
        ModelState.AddModelError("UserId", "You must select a user!");
    /*Do some validation here*/
    //ModelState.Add("Name", "You must set the user name!")
    return ModelState.IsValid;
}

View

@model StackOverFlowExample.Models.Employee
@{
    MembershipUser user = null;
    ViewBag.Title = "Mirko Example";
    var users = ViewBag.Users as IEnumerable<SelectListItem>;
}

@if (TempData["message"] != null) {
    user = TempData["user"] as MembershipUser;
    <h3>@TempData["message"]</h3>
    <div>
        <span>You selected @user.UserName</span>
        <ul>
            <li>Email: @user.Email</li>
            <li>Last Logged In: @user.LastLoginDate.ToString("d")</li>
            <li>Online: @user.IsOnline</li>
        </ul>
    </div>
}

@using (@Html.BeginForm()) { 
    <label for="UserId">Associate Employee To User:</label>
    @Html.DropDownListFor(m => m.UserId, @users)
    @Html.HiddenFor(m => m.Name)                                               
    <input type="submit" value="Save" id="save-employee"/>
}
<div id="status" style="display:none;"></div>

<script type="text/javascript">
    $(document).ready(function () {
        $("#UserId").change(function () {
            //Set value of name 
            $("#Name").val($(this).children("option:selected").text());            
        });
        $("#save-employee").click(function (e) {
            var value = $("#Name").val();
            if (value == "" || value == "na") {
                e.preventDefault();
                $("#status").html("<h3>You must select a user!</h3>").toggle();
            }
        });
    });
</script>

来源：https://stackoverflow.com/questions/9399486/asp-net-mvc-3-dropdownlist-of-users