ASP.NET MVC 3 用户下拉列表

Question

在我的应用程序中，我已将UserId 关联到数据库中的一个表。我需要在创建新项目时从下拉列表中选择用户名。并且'可以用元素 viewbag 做到这一点吗？

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

我使用默认的会员提供程序，所以我不能使用实体框架来解决这个问题

编辑

编辑 2

这是我的创建动作：

[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();
}

这不起作用。错误是：

无法将类型'string[]'隐式转换为'string'

Employee我的模型

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 
            }
        }

    }
}

查看：

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

我在UserId 字段中的结果不是UserId，而是000000-000000-0000000-00000

Answer 1

如何将用户列表设置为 ViewBack 中的 SelectItem 是的，您应该能够通过将您的收藏传递给 ViewBag 来做到这一点，然后从中创建您的下拉列表：

在你的控制器中

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

在您的视图中（如果您使用的是 Razor）

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

在此处阅读有关 SelectListItem 的更多信息：

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

也可以看看：

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

问题变成了更多。这是我解决问题的想法：

控制器：

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;
}

查看

@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>