从mvc3 DropDown列表中渲染并选择数据

Question

简单的情况

一个对象用户有许多UserGroup.

我想在mvc3表单编辑或创建操作上实现从下拉列表中选择UserGroups.

控制器:

private List<User> GetAllUsers()
{
    List<User> users;
    users = find all users to List...
    return users;
}

public ActionResult Edit(Guid Id)
{
   ViewBag.UserGroups = new SelectList(GetAllUsers(), "UserId", "Name");
   return View();
}

视图:

<div class="editor-label">
    @Html.LabelFor(model => model.UserGroupId, "UserGroupId")
</div>
<div class="editor-field">
    @Html.DropDownList(WHAT TO PUT HERE ?);
    @Html.ValidationMessageFor(model => model.UserGroupId)
</div>

Answer 1

哦,请使用视图模型,切掉ViewBag的垃圾,每次看到它都会让我生病.

public class UserViewModel
{
    public int UserGroupId { get; set; }
    public IEnumerable<SelectListItem> UserGroups { get; set; }
}

然后:

public ActionResult Edit(Guid Id)
{
    var model = new UserViewModel
    {
        UserGroups = new SelectList(GetAllUsers(), "UserId", "Name")
    }
    return View(model);
}

并在视图中:

@model UserViewModel
...
<div class="editor-label">
    @Html.LabelFor(model => model.UserGroupId, "UserGroupId")
    </div>
    <div class="editor-field">
        @Html.DropDownListFor(x => x.UserGroupId, Model.UserGroups);
        @Html.ValidationMessageFor(model => model.UserGroupId)
    </div>
</div>

但如果你想让我生病并保持ViewCrap:

@Html.DropDownListFor(
    x => x.UserGroupId, 
    (IEnumerable<SelectListItem>)ViewBag.UserGroups
)