ASP.NET MVC bug binding collection of DropDownList?

I have a view with 1 dropdown generated from Model property and 3 additional dropdowns that are generated from array property

@Html.DropDownListFor(m => m.AgentType, Model.AgentTypeListItems)
@for (int i = 0; i < Model.AgentTypes.Length; i++)
{
    @Html.DropDownLi开发者_运维知识库stFor(m => m.AgentTypes[i], Model.AgentTypeListItems)
}

The controller method initializes AgentTypeListItems collection + sets default values for AgentType dropdown and 3 dropdowns for the collection:

var model = new OptionsViewModel();

// for DropDownListFor
model.AgentTypeListItems = new[]
{
    new SelectListItem { Text = "1", Value = "1" }, 
    new SelectListItem { Text = "2", Value = "2" },
    new SelectListItem { Text = "3", Value = "3" },
};

// 1 dropdown in the model
model.AgentType = "2";

// 3 dropdowns in array
model.AgentTypes = new[] { "3", "2", "1" };

return View(model);

When I open it in browser I get "2" everywhere though AgentTypes array was initialized with different values(!):

When I replace DropDownListFor with TextBoxFor:

@Html.TextBoxFor(m => m.AgentTypes[i])

I get the correct values in the inputs (!):

It means the TextBoxFor works as expected, but DropDownListFor doesn't.

Is it a bug in MVC DropDownListFor?

UPDATE Here is the model class:

public class OptionsViewModel
{
    public SelectListItem[] AgentTypeListItems { get; set; }
    public string AgentType { get; set; }
    public string[] AgentTypes { get; set; }
}

---

I know that this post is more than a year old but it seems still to be a bug. Replacing

@Html.DropDownListFor(m => m.AgentType, Model.AgentTypeListItems)
@for (int i = 0; i < Model.AgentTypes.Length; i++)
{
    @Html.DropDownListFor(m => m.AgentTypes[i], Model.AgentTypeListItems)
}

with

@Html.DropDownListFor(m => m.AgentType, Model.AgentTypeListItems)
@for (int i = 0; i < Model.AgentTypes.Length; i++)
{
    @Html.DropDownListFor(m => m.AgentTypes[i], new SelectList(Model.AgentTypeListItems, "Value", "Text", Model.AgentTypes[i])
}

works for me.

---

comment out your first line, @Html.DropDownListFor(m => m.AgentType, Model.AgentTypeListItems) what happens then?

Try this:

        @for (int i = 0; i < Model.AgentTypes.Length;  i++)
        {     
            string selected = Model.AgentTypes[i];
            @Html.DropDownListFor(m => selected, new SelectList(Model.AgentTypeListItems, "Text", "Value",Model.AgentTypes[i]))
        }

---

I wonder if this is similar to situations in WPF and Windows Forms where using the same source item for the list choices "links" all the UI elements together behind the scenes? I recall having to create separate copies of the list object in those situations. Might be worth a try here.