F＃中的CLI事件的C＃类事件访问器 [英] C#-style event accessors for CLI events in F#

问题描述

  let event = new DelegateEvent< EventHandler>（）
 member x.Ping（）= event.Trigger（[| x; EventArgs.Empty |]）
 [< CLIEvent>] 
 member x.PingEvent = event.Publish 
  

但是，我希望在处理程序被添加或删除时运行一些代码。我认为这可以在C＃中这样做：

  public event EventHandler PingEvent 
 {
 add 
 {
 //做某事
} 
删除
 {
 //做某事
} 
} 
  

如何在F＃中写上面？

解决方案

在F＃中，您可以使用 IDelegateEvent< _> 接口（或 IEvent< _> 或 IEvent <_，_> 从它派生的接口）。所以你可以这样做：

  let customEvent add remove = 
 {new IDelegateEvent< _> 
成员this.AddHandler del = add del 
 member this.RemoveHandler del = remove del} 
 
 type MyType（）= 
 let ev = customEvent（* your添加处理程序*）（*你的删除处理程序*）
 
 [< CLIEvent>] 
成员this.myEvent = ev 
  

I am exposing an event from F# to C# like this:

let event = new DelegateEvent<EventHandler>()
member x.Ping() = event.Trigger([| x; EventArgs.Empty |])
[<CLIEvent>]
member x.PingEvent = event.Publish

But I'd like some code to run whenever handlers are added or removed. I think this can be done in C# like this:

public event EventHandler PingEvent
{
    add 
    {
        //do something
    }
    remove
    {
        //do something
    }
}

How do I write the above in F#?

解决方案

In F#, you can define events with implementations of the IDelegateEvent<_> interface (or the IEvent<_> or IEvent<_,_> interfaces which derive from it). So you can do something like this:

let customEvent add remove =
  { new IDelegateEvent<_> with
        member this.AddHandler del = add del
        member this.RemoveHandler del = remove del }

type MyType() =
  let ev = customEvent (* your add handler *) (* your remove handler *)

  [<CLIEvent>]
  member this.myEvent = ev

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