what's mean += operator in eventchanged event

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1.80/5 (3 votes)

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Hi all
whats mean += operator in .eventchanged event in control that invoke and what's related to delegate?

which part of complete C# book related to this subject ?

thanks a lot.

Posted 5-Sep-15 21:15pm

bernova

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4 solutions

Solution 1

It's the syntax used to add an event handler to the chain of existing handlers.
See here: https://msdn.microsoft.com/en-gb/library/aa645739%28v=vs.71%29.aspx?f=255&MSPPError=-2147217396[^]

[edit]typo: "an" for "add"[/edit]

Posted 5-Sep-15 21:28pm

OriginalGriff

Updated 5-Sep-15 21:43pm

v2

Comments

bernova 6-Sep-15 3:31am

Thanks a lot.

OriginalGriff 6-Sep-15 3:42am

You're welcome!

Kornfeld Eliyahu Peter 6-Sep-15 3:32am

Opened a reading class this morning? :-)

OriginalGriff 6-Sep-15 3:42am

:laugh:

bernova 6-Sep-15 3:42am

what do you mean?

Kornfeld Eliyahu Peter 6-Sep-15 3:45am

That this is an answer of RTFM...

[no name] 6-Sep-15 10:37am

I lost one of my small 5 here

Solution 2

+= adds the delegate to the internal list of handlers for the event and -= removes it from the list.

Here is a detailed explanation by John Skeet
Delegates and Events in C#[^]

Posted 5-Sep-15 22:01pm

Suvendu Shekhar Giri

Solution 3

Check Delegates in a book for more information on this topic.

Posted 5-Sep-15 23:08pm

Abhinav S

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Sergey Alexandrovich Kryukov · Accepted Answer · 2015-09-06T04:18:00

Solution 4

The operator adds an event handler to the invocation list of some event instance. Interestingly, the added element is a delegate instance, which has its own invocation list. But implementation of the operator if quite non-trivial; it does not produce a tree structure. For further detail, please see this section of my article
Dynamic Method Dispatcher, 4.1 On the Nature of Delegate Instance.

—SA

Posted 6-Sep-15 4:18am

Sergey Alexandrovich Kryukov

Comments

[no name] 6-Sep-15 10:41am

I don't have that much 5's but I spend one here because "Dynamic Method Dispatcher" is very helpfull.

Sergey Alexandrovich Kryukov 7-Sep-15 1:45am

Thank you very much.
—SA

bernova 6-Sep-15 11:10am

thanks Sergey Alexandrovich Kryukov

Sergey Alexandrovich Kryukov 7-Sep-15 1:46am

You are very welcome.
—SA