Populating ASP.NET MVC DropDownList

问题:

OK, I've been Googling for hours and trying everything and can't get anything to work. I am learning MVC using Sharp Architecture and have generated some basic forms for creating Client objects. I want to fill the state drop down list with a list of US states and let the user pick from that list. I am able to populate the list and get the value back (to save the client) but when I go to edit the client, the client's current state is not selected. I have set the selected value in the SelectList:

<li>
    <label for="Client_StateProvince">StateProvince:</label>
    <div>
        <%= Html.DropDownListFor(c=>c.Client.StateProvince, new SelectList(Model.StateProvinces, "id", "Name", Model.Client.StateProvince), "-- Select State --")%>
    </div>
    <%= Html.ValidationMessage("Client.StateProvince")%>
</li>

This does not seem to be good enough. What am I missing?

回答1:

<%= Html.DropDownListFor(c => c.Client.StateProvince.Id, 
                              new SelectList(Model.StateProvinces, 
                                             "id", 
                                             "Name", 
                                             Model.Client.StateProvince), 
                              "-- Select State --")%>

This does it.

Hope this helps someone else.

~Lee

回答2:

Worked perfectly for me thanx! I used it to set a parent relation on a subcategory:

<%= Html.DropDownListFor(
 model => model.Category.ParentId,
 new SelectList(Model.Categories,
 "CategoryId",
 "Name",
  Model.Categories.Where(x => x.CategoryId == Model.Category.ParentId).Single()))%>

Jeroen

回答3:

I did it this way. Works well.

Controller

IFarmModelInterface service2 = new FarmModelRepository();
ViewData["Farms"] = new SelectList(service2.GetFarmNames(), "id", "FarmName", "XenApp");

View

<%: Html.DropDownListFor(m => m.Farm, (ViewData["Farms"] as SelectList)) %>

回答4:

public ActionResult  AllUsers()
{
    List<Users> users = userRep.GetUsers();
    var listUsers = (from u in users.AsEnumerable()
                     select new SelectListItem
                     {
                        Text = u.UserName,
                        Value = u.UserId.ToString(),
                        Selected = (u.UserId==6)
                     }).AsEnumerable();
    ViewBag.ListItems = listUsers;
    //ViewBag.SelectedItem = 2;
    return View();
}

In AllUsers.cshtml

<p>@Html.DropDownList("ListItems")</p>

回答5:

<%= Html.DropDownListFor(c => c.Client.StateProvince, new SelectList(Model.StateProvinces, "Id", "Name")) %> 

and override ToString() for StateProvince to return Id, i.e.:

return Id.ToString();

This works but is not a perfect solution...

Dennis

回答6:

This is View - MVC Controller

@Html.DropDownListFor(m => m.Entity, new ABC.Models.DropDownPopulate().MyMethod, new { @class = "form-control input-inline input-medium" })

MyMethod Get Data List Bind With Dropdown Using SelectListItems

 public List<SelectListItem> MyMethod
        {
            get
            {
                List<SelectListItem> dropdownList = new List<SelectListItem>();
                var items = new DropDown_Bl().GetAll();
                foreach (var item in items)
                {
                    SelectListItem dropdownItem = new SelectListItem();
                    dropdownItem.Value = item.RnID.ToString();
                    dropdownItem.Text = item.Description;
                    dropdownList.Add(dropdownItem);
                }
                dropdownList.Insert(0, new SelectListItem() { Text = "Please Select", Value = "", Selected = true });
                return dropdownList;
            }
        }

GetAll Method In Dropdown_Bl - Used to get data as list from database

  public List<My_Table> GetAll()
        {
            var Items = _Context.MyRepository.GetMany(q => q.Area == "ASD").ToList();
            return Items ;
        }

回答7:

public ActionResult  AllUsers() {
    List<Users> users = userRep.GetUsers();
    var listUsers = (from u in users.AsEnumerable()
                     select new SelectListItem
                     {
                        Text = u.UserName,
                        Value = u.UserId.ToString(),
                        Selected = (u.UserId==6)
                     }).AsEnumerable();
   // ViewBag.ListItems = listUsers;
   ViewData["tempEmpList"]=listUsers;
    return View(); }

Fill Dropdown

@Html.DropDownList("SelectedEmployee", new SelectList((IEnumerable) ViewData["tempEmpList"], "Id", "Name"))