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what is the purpose of "this.lblDelete.Click += new System.EventHandler(this.lblDelete_Click); " in InitializeComponent() method in C#? [duplicate]

This question already has answers here:
Understanding events and event handlers in C#
(13 answers)
Closed 4 years ago.
I am a newbie to asp.net, can you please explain the line of code below?
this.lblDelete.Click += new System.EventHandler(this.lblDelete_Click);
I don't know much about events and delegates.

Essentially the code attaches an event handler to an event so that it can be, well... handled.
A simple way to understand it would be.
This event:
this.lblDelete.Click
Has this event handler attached:
+= new System.EventHandler
Which calls this method:
lblDelete_Click

What is the point of assigning an empty delegate to an event? [duplicate]

This question already has answers here:
Event declaration with assignment to empty delegate
(2 answers)
Closed 8 years ago.
I have just come across this code in a book I'm working through:
public event EventHandler<ProjectEventArgs> ProjectUpdated = delegate { };
Is setting a delegate here merely to ensure ProjectUpdated is never null, and this avoid the standard null check before firing the event?

Normally, when you are to raise an event, you have to check for null values, meaning, no event handlers attached. With this approach, you can skip this check, because the event will always have an empty handler.

When is it necessary to manually decrement an event handler [duplicate]

This question already has answers here:
Is it bad to not unregister event handlers?
(2 answers)
Closed 9 years ago.
There is a small event handler example at msdn
with the line:
myNewLog.EntryWritten += new EntryWrittenEventHandler(MyOnEntryWritten);
Presumably this adds the triggering event to a queue to be handled. What removes the handler from the queue? Do I even need to think about this?

The "-=" operator removes the subscriber from the publisher. Not unsubscribing is a problem when the publisher of the event will live longer than the subscriber.
More info here and here.

Unsubscribing events syntax in .NET [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
Is there an actual difference in the 2 different ways of attaching event handlers in C#?
I'm working on a .NET application and I ran into a small syntax dilemma. I noticed there were two ways of unsubscribing from an event and I'm curious. Is there any difference between the two, or are they equal? Is there any scenario, when they may act differently? Compiler doesn't seem to have problem with either of those.
object.myEvent += new EventHandler(callback_function);
object.myEvent -= new EventHandler(callback_function);
and
object.myEvent += new EventHandler(callback_function);
object.myEvent -= callback_function;
Thanks

There isn't any difference.
You could also have:
object.myEvent += callback_function;
object.myEvent -= callback_function;
The compiler does some nifty type inference which makes code readability a lot better!

Wrapping a delegate in the EventHandler is redundant. You can always drop it even though it is a part of the standard template.
Resharper gives you a warning about this

Subscribing and Unsubscribing of Events [duplicate]

This question already has answers here:
Is it bad to not unregister event handlers?
(2 answers)
Closed 9 years ago.
I have a Winform, i have added a few controls like Textbox, buttons.
I subscribed to the textbox Changed event, teh button click event.
The designer automatically adds the += statements i.e subsribtion of events in the
designer.cs file.
My question is should we add the unregisterig of these events in the dispose function ?
is it necesssary, or will there be any leak if i do not unregister.
Or is it that .NET takes care of it.

Refers to following link:
Is it bad to not unregister event handlers?

This is not required to unregister events that is subscribed on same class.

If your WinForm is the only one that is consuming/subscribing to it, then you dont need to worry about unsub.