English 中文(简体)
Can an event be used as an event listener?
原标题:
  • 时间:2009-11-14 11:04:22
  •  标签:
  • c#
  • events

I m trying to expose some events from a private object which is contained inside the object I am creating and it looks like the compiler is happy with this:

private WindowUpdateServer _windowUpdateServer;

public event WindowUpdateHandler WindowUpdated;

public RecieveWindowFramesManager() {

    _windowUpdateServer = new WindowUpdateServer();

    _windowUpdateServer.ExistingWindowUpdated += WindowUpdated; // ExistingWindowUpdated is a WindowUpdateHandler
}

But after RecieveWindowFramesManager is initialized _windowUpdateServer.ExistingWindowUpdated == null.

Am I missing something here - it seems this should work?

It is worth noting that after RecieveWindowFramesManager is initialized I attach an event listener to WindowUpdated but it never gets called (even though _windowUpdateServer.ExistingWindowUpdated gets fired).

最佳回答

I d do something like this:

public event WindowUpdateEventHandler WindowUpdated
{ 
    add{ _windowUpdateServer.ExistingWindowUpdated += value; }
    remove{ _windowUpdateServer.ExistingWindowUpdated -= value; }
}

It has some issues if you re actually using the sender argument in the event handlers, though; it ll point to the inner object rather than the one you re getting the events from.

问题回答

I m not sure, but I think this only assigns those handlers from the WindowUpdated event, that were set when the += operation took place. Since it is a constructor, the list was empty. To do what you want, create your own event handler for ExistingWindowUpdated and fire the WindowUpdated event from there.





相关问题
Anyone feel like passing it forward?

I m the only developer in my company, and am getting along well as an autodidact, but I know I m missing out on the education one gets from working with and having code reviewed by more senior devs. ...

NSArray s, Primitive types and Boxing Oh My!

I m pretty new to the Objective-C world and I have a long history with .net/C# so naturally I m inclined to use my C# wits. Now here s the question: I feel really inclined to create some type of ...

C# Marshal / Pinvoke CBitmap?

I cannot figure out how to marshal a C++ CBitmap to a C# Bitmap or Image class. My import looks like this: [DllImport(@"test.dll", CharSet = CharSet.Unicode)] public static extern IntPtr ...

How to Use Ghostscript DLL to convert PDF to PDF/A

How to user GhostScript DLL to convert PDF to PDF/A. I know I kind of have to call the exported function of gsdll32.dll whose name is gsapi_init_with_args, but how do i pass the right arguments? BTW, ...

Linqy no matchy

Maybe it s something I m doing wrong. I m just learning Linq because I m bored. And so far so good. I made a little program and it basically just outputs all matches (foreach) into a label control. ...

热门标签