F＃使用HttpPostedFileBase（抽象类作为成员类型）(F# using HttpPostedFileBase (abstract class as member type))

 我一直在将我的MVC模型/表单从C＃转换为F＃库，但似乎无法解决这个问题。 我在原始的C＃模型中使用HttpPostedFileBase ，但我很困惑如何编写一个以类似方式工作的F＃类型。 
 
// C#
public class UploadForm()
{
    public int ItemID { get; set; }
    public string Email { get; set; }
    public HttpPostedFileBase UploadFile { get; set; }
    // UploadFile is the name of the HTML file input on the Razor view
}
 
// F#
type UploadForm() = 
    member val ItemID = 0 with get, set
    member val Email = "" with get, set
    member val UploadFile = ???
 
 我阅读了关于抽象属性的F＃文档，但我没有覆盖任何属性...只是试图说一个给定的成员（UploadFile）应该是某种类型（HttpPostedFileBase）。 这是可能的还是我需要编写支持代码？ 

I've been converting my MVC Models/Forms from C# into an F# library, but can't seem to figure this one out. I use HttpPostedFileBase in the original C# model, but I'm confused how to write an F# type that would work in a similar fashion.
 
// C#
public class UploadForm()
{
    public int ItemID { get; set; }
    public string Email { get; set; }
    public HttpPostedFileBase UploadFile { get; set; }
    // UploadFile is the name of the HTML file input on the Razor view
}
 
// F#
type UploadForm() = 
    member val ItemID = 0 with get, set
    member val Email = "" with get, set
    member val UploadFile = ???
 
I read the F# documentation on abstract properties, but I'm not overriding any properties here... just trying to say that a given member (UploadFile) should be of a certain type (HttpPostedFileBase). Is this possible or do I need to write backing code?

原文：https://stackoverflow.com/questions/29129831