你如何在F＃中实现一个接口

Question

我在C＃中有一个接口，如下所示：

public interface IMessageOptions
{
    int ReceiveTimeout { get; set; }
    int PeekTimeout { get; set; }
    bool Transactional { get; set; }
}

我试图在F＃中实现它：

type Settings() =
    interface IMessageOptions with
        member this.PeekTimeout: int with get, set
        member this.ReceiveTimeout: int with get, set // error at start of this line
        member this.Transactional: bool with get, set

但是在第一个属性之后我得到了一个错误：

  

“模式中此点或之前的不完整结构化构造”

应该怎么写？

此上下文中是否不允许使用自动属性？

Answer 1

以下是其语法：

type Settings() =
   interface IMessageOptions with
      member val PeekTimeout = 0 with get, set
      member val ReceiveTimeout = 0 with get, set
      member val Transactional = false with get, set

区别在于：

• 使用val代替this.
• 明确定义默认值
• 您不必指定类型（尽管可以）

作为参考，以下是如何在F＃中定义界面本身：

type IMessageOptions =
  abstract member PeekTimeout : int with get, set
  abstract member ReceiveTimeout : int with get, set
  abstract member Transactional : bool with get, set

Answer 2

如果您想要自动实施属性，请this is the syntax：

type Settings() =
    interface IMessageOptions with
        member val PeekTimeout : int = 0 with get, set
        member val ReceiveTimeout : int = 0 with get, set
        member val Transactional : bool = false with get, set

请注意，您必须明确定义默认值。