Question

我正在尝试从本文http://www.codeproject.com/Articles/35532/C-COM-Object-for-Use-In-JavaScript-HTML-Including

翻译成F＃代码

我偶然发现了这条线：

public delegate void MyFirstEventHandler(string args);
public event MyFirstEventHandler MyFirstEvent;

我试图在F＃中将其翻译为：

type MyFirstEventHandler = delegate of string -> unit
type MyFsComComponent () = 
    let my_event = new Event<MyFirstEventHandler,string> ()

    [<CLIEvent>]
    member x.MyFirstEvent = my_event.Publish

我得到：'MyFirstEventHandler'有一个非标准委托

我可以编译：

type MyFirstEventHandler = delegate of obj*string -> unit

但这不是COM控制所需要的。

C# to F# class transition中也提出了这个问题 - “公共事件”仍然没有解决方案

解决。感谢Leaf Garland

type MyFirstEventHandler = delegate of string -> unit
type MyFsComComponent () =    
    let my_event = new DelegateEvent<MyFirstEventHandler> ()

    [<CLIEvent>]
    member x.MyFirstEvent = my_event.Publish

诀窍。

Answer 1

F# Event类期望参数类型为通用参数，而不是委托类型。它还期望委托是标准类型（例如obj*eventargs->unit）。对于任意委托，请使用DelegateEvent。

type MyFirstEventHandler = delegate of string -> unit
type MyFsComComponent () = 
    let my_event = new DelegateEvent<MyFirstEventHandler>()

    [<CLIEvent>]
    member x.MyFirstEvent = my_event.Publish

什么是F＃相当于C＃“公共事件”

1 个答案: