Peter,
In this situation, I would recommend that you give the object some sense
of the index that it is at. For example, when you assign it in an array,
you would assign a property indicating the index in the array it is at.
However, I can see where people would cringe at this.
You might want to consider having a wrapper for the array which exposes
the event. The EventArgs-derived class would have an index on it,
indicating the index of the item that fired the event, and the sender would
have the actual object.
I'm curious though, what do you need the index of the item in the array
for if you have the sender?
--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)
Peter Krikelis said:
Nicholas,
Thanks for the clarification.
However, is there another way of doing that? The reason I ask is because
if
you have an array of a 100,000 objects theoretically, then looping through
the entire array would be expensive. Compund it with the fact that the
events
are happening fairly quickly and in repeated succession.
Is there a way of passing a handle of the specific array object to the
class
that raises the event handler, and return that handle with the event data?
Thank you,
Pete.
Nicholas Paldino said:
Peter,
Yes, I do. I assume the event handler has access to the original
object
array. In this case, enumerate through each of these elements in the
array,
comparing the object reference (use the static ReferenceEquals method on
object to be sure) to the sender.
--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)
message
Nicholas,
I think you were the one to point me to the paradigm of event handlers
in
the first place. I did that.
My event handler now takes arguments of "sender" type object and
"derivedEventArgs" which derives from System.EventArgs.
What I was looking for is how to compare object references or cycle
through
that array. Do you mean using a for loop?
Thanks,
Pete.
:
Peter,
Yes, there is. Since you would be using one event handler for all
the
items in the array, you can cycle through the array and then compare
object
refrences with the sender of the object (this is assuming you followed
the
pattern for event handlers, where the first parameter is the object
that
fired the event, the second is of type EventArgs or derived from
EventArgs.
Don't worry, I'll wait while you make the changes. Done? Ok =) ).
Once
you do that, you will have your index.
Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)
message
Hi,
Finally figured events and delegates whew! Thanks to the people in
this
community that helped me out.
So now I have a class that raises an event.
Now if I instantiate an object array of that class, and the event
fires,
is
there any way of getting the array index of the object that raised
that
event?
Thanks in advance.
Pete.