ISerializable - Roy Osherove's Blog

Cool!

You can also save on creating a new EventArgs object each time an event is fired by using the EventArgs.Empty object.

EventArgs.Empty probably should do a thread check and return a single eventargs instance per thread... I wonder how this would affect performance?

Or sacrifice the per thread check and EventArgs becomes an AppDomain singleton, maybe eases the GC a little, hmmm...

In Whidbey, you'll be able to do this in VB as well. See http://www.panopticoncentral.net/archive/2004/08/06/1545.aspx

Eric,

EventArgs.Empty follows the Null Object pattern and is a static readonly immutable object so inherently thread-safe. Guid and String use the same pattern.

I'm not sure if my comment here is a little late on the subject.... However, according to an article in the MSDN Library, the "pattern" presented in this article, for storing delegates in the EventHandlerList, is for saving up memory allocation. It states that each event causes the compiler to allocate memory to store event information, so if you have a situation where you have multiple events, you'd rather use an EventHandlerList. Here's the link to "How to: Declare Events That Conserve Memory Use". http://msdn2.microsoft.com/en-us/library/yt1k2w4e.aspx Further more, this "pattern" for using the EventHandlerList (also visible by reverse-engineering .NET Control code), states that you should define a "static readonly object" as the key variable. This is probably due to the possibility of saving memory too, in case you're using multiple controls of the same type and you wish to lay low on memory allocated for keys (but this is only an assumption). "How to: Handle Multiple Events Using Event Properties" http://msdn2.microsoft.com/en-us/library/8843a9ch.aspx Therefore, although the article addresses an important subject, the "code look very messy" claim is not an accurate one, because you're still supposed to define multiple "static readonly object" keys, so your code still remains "messy". The actual usage of this pattern is for saving up memory. Finally, this entire comment is written from a "Control development" perspective, so you can clearly state that the example is good enough for the claims given, when discussing "other purposes"... So feel free to completely disregard it... Thanks.

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