What is the difference between Event and Delegates

Question

1.00/5 (1 vote)

See more:

What is the difference between Event and Delegates. In lots of places we have to faced this question. But not from every sites we got right answer.

Posted 20-Apr-11 18:16pm

Prasanta_Prince

Add a Solution

5 solutions

Solution 3

SA already given you a perfect solution In addition to his answer my answer is
Delegates and Events Both are related.
Dalegete is a function pointer which can able to store the address of any function with same prototype where as Event is a function handler which can handles or run the functions in same prototype of its delegate.So for handling events delegate is used.
Take a look there[^] to read a Nice article which focusing on Delegate and Events. Its not too much you can get plenty of article and Solutions over Google which will easily guide you what's the difference.

Posted 20-Apr-11 18:46pm

RaviRanjanKr

Updated 20-Apr-11 18:53pm

v3

Comments

Sergey Alexandrovich Kryukov 21-Apr-11 1:37am

Sorry, Ravi, this is not accurate. If you examine a delegate instance, you will see it is a... class, and it contains an invocation list with one or more "function pointer". And even each of the pointers is not like a function pointer, it also contains "this" (null for static handlers), otherwise how a non-static method could be called? Not so simple.

The major difference between event and a delegate is event limitations and the binding of to generic EventHander. This topic also would need a short article. "So for handling events delegate is used" is not accurate. As someone noticed, the relationship between event and delegate instance resembles the one between property and field (setter/getter), you can program side effect of += and -+.

--SA

GlobX 21-Apr-11 1:44am

SA, beautiful response - it's not often you find someone with the ability to tell someone they're wrong without being harsh or rude :)

Sergey Alexandrovich Kryukov 21-Apr-11 2:43am

Thank you for your good words.
Well, very many people say I am harsh -- I have a different culture where your best friend will never miss a chance to hit your face in dirt (in terms of understanding science, if you try to pretend you're an "expert"). Such relationships is a good school which teaches positive acceptance of criticism and self-improvement. People respect each other when the challenge like that but will not respect anyone getting criticism as offense. Here in US I often see people who would get it as an offense if you simply say "You solution will not work", not everyone, but... How to do engineering in this case?
--SA

RaviRanjanKr 21-Apr-11 3:08am

hey SA! I am a student of Computer Science and I always looking for expert advice. I respect to my elders and seniors like you.
CP gives me a great platform for learning and sharing knowledge.
and I will keep looking to learn a lots of thing from you and other experts of CP. :)

Sergey Alexandrovich Kryukov 21-Apr-11 3:37am

I really respect your active and interested learning; it looks like you already doing good; It's my pleasure to work with such people!

(I hope you understand that we discussed harshness and attitude to criticism in different people with GlobX, in contrast with you; for example, see the reference to a comment to my other answer below).

Respect,
--SA

RaviRanjanKr 21-Apr-11 3:46am

Yeah! I've read the crap comment by phunsukh wangdu.
your answer is perfect according to OP question.

Sergey Alexandrovich Kryukov 21-Apr-11 4:01am

You see... I only can reiterate that you take criticism with decency and constructively (I hope, me too :-); and this is one of the important keys not just to learning but to everyday work, too. My pleasure.

Cheers,
--SA

Sergey Alexandrovich Kryukov 21-Apr-11 3:32am

@GlobX: Here is a classical recent example of some attitude, take a look:
http://www.codeproject.com/Answers/184783/Tab-control-in-Csharp-code-behind.aspx
(comment on my answer).
What do you say? :-)
--SA

RaviRanjanKr 21-Apr-11 1:58am

Excellent Suggestion.
Yeah! I agree to you! my answer was not perfect.
Thanks for spot me SA :)

Sergey Alexandrovich Kryukov 21-Apr-11 2:36am

You're very welcome. The thing is -- the topic is not very trivial -- I'm writing an article related to is ("Dynamic method dispatcher"), found a lot of depth showing up only in advanced code...
--SA

Prasanta_Prince 21-Apr-11 5:02am

Good solution. Thank you.

Solution 1

try these links

http://msdn.microsoft.com/en-us/library/17sde2xt(v=vs.71).aspx[^]

http://blog.monstuff.com/archives/000040.html[^]

Posted 20-Apr-11 18:26pm

nit_singh

Comments

Prasanta_Prince 21-Apr-11 5:02am

Good solution. Thank you.

RaviRanjanKr 21-Apr-11 8:15am

Thank you Prasanta :)

Solution 4

Hope this[^] might help you.

Posted 20-Apr-11 19:53pm

Ramalinga Koushik

Solution 5

As Appendix to SA. I find this CP article very help full C# Event Implementation Fundamentals, Best Practices and Conventions[^]. I have learned a lot from this articel about events and delegates. At first in C# I self was confused about the differences and how it works.

Posted 20-Apr-11 19:53pm

Kim Togo

Updated 21-Apr-11 22:21pm

v2

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sergey Alexandrovich Kryukov · Accepted Answer · 2011-04-20T18:27:00

Solution 2

What's wrong with standard MSDN overview: http://msdn.microsoft.com/en-us/library/17sde2xt.aspx[^]?

Many experts would provide good answers, but I'm not sure it would justify the time spend. Start reading about these concepts and do simple exercises to get a feel of it and remove misunderstanding. When something is not clear, ask some more concrete questions — I would be happy to help, or someone else will. If you know all what can be considered as a prerequisite to these topics, it could be understood pretty fast, but I cannot say it is trivial — not at all.

[EDIT]

Please also see my comment to the answer by Ravi.

Finally, I would like to add that understanding of delegates, delegate instances (notice the difference) and events need significant effort, but after basic usage pattens are learned the usage is very easy and safe.

—SA

Posted 20-Apr-11 18:27pm

Sergey Alexandrovich Kryukov

Updated 20-Apr-11 20:29pm

v3

Comments

Michel [mjbohn] 21-Apr-11 1:29am

my 5

Sergey Alexandrovich Kryukov 21-Apr-11 1:30am

Thank you very much.
--SA

Ankur^\m/ 21-Apr-11 1:46am

Many experts would provide good answers, but I'm not sure it would justify the time spend.
I can't agree more. The topic is already very well explained (MSDN and other articles).

good advice, my 5!

Sergey Alexandrovich Kryukov 21-Apr-11 2:28am

Thank you, Ankur.
(I you don't mind, I fixed a typo (copied from mine, fixed, too, sorry) and one usage mistake...)
--SA

Kim Togo 21-Apr-11 1:53am

My 5.

Sergey Alexandrovich Kryukov 21-Apr-11 2:28am

Thank you, Kim.
--SA

RaviRanjanKr 21-Apr-11 1:58am

Excellent Answer! My 5 :)

Sergey Alexandrovich Kryukov 21-Apr-11 2:29am

Thank you, Ravi.
--SA

Prasanta_Prince 21-Apr-11 5:01am

Good solution. Thank you.

Sergey Alexandrovich Kryukov 21-Apr-11 5:19am

Thank you, Prasanta.
--SA

NandaKumer 2-Jun-11 10:17am

Why you answered this question ? He is a "Team Leader". He has to know this minor thing before he leads somebody.Don't you think ?

Sergey Alexandrovich Kryukov 2-Jun-11 13:26pm

I absolutely agree, Nanda.
A team lead can lead successfully if she/he has respect of all members; and good engineers will disrespect ignorance. Unfortunately, in real life... this is a problem.
--SA