C# 使用非基本体对象为DropDownListFor实现Equals

我有一个对象

Modem

，其属性为

Protocol

，它绑定到

DropDownListFor

。未选择DropDownList中调制解调器的值

public class Modem {

   public Protocol Protocol { get; set; }

}

public class Protocol {
    public string Name { get; set; }
    public string Value { get; set; }
}

我的控制器代码

var modem = new Modem{ Protocol = new Protocol { Name = "UDP", Value = "The udp protocol" } };
var protocols = new List<Protocol>{ new Protocol { Name = "TCP", Value = "The tcp protocol" }, new Protocol { Name = "UDP", Value = "The udp protocol" } };
ViewBag.Protocols = protocols.Select(p => new SelectListItem{ Value = p.Name, Text = p.Value });

return View(modem);

更新： 我试着用

@Html.DropDownListFor(modem => modem.Protocol, new SelectList(ViewBag.Protocols, "Name", "Value", Model.Protocol))

但也不起作用：（

更新2: 使用reflector，我发现了这条线：

HashSet<string> set = new HashSet<string>(from value in enumerable.Cast<object>() select Convert.ToString(value, CultureInfo.CurrentCulture), StringComparer.OrdinalIgnoreCase);

---

---

您根本不需要实现

Equals

-只需在POST处理操作中执行从

SelectListItem.Value

到

协议

类的反向映射。我不明白。显示表单时，我希望DropDownList具有模型。协议具有默认值。

@Html.DropDownListFor(modem => modem.Protocol, new SelectList(ViewBag.Protocols, "Name", "Value", Model.Protocol))

HashSet<string> set = new HashSet<string>(from value in enumerable.Cast<object>() select Convert.ToString(value, CultureInfo.CurrentCulture), StringComparer.OrdinalIgnoreCase);

public override string ToString()
{
    return Name;
}