Removing All Event Handlers

  • Thread starter Thread starter MuZZy
  • Start date Start date
M

MuZZy

Hi,

Is there a way to remove all event handlers for a control's event? Say, i have a button and i want
to remove all button.Click events for it - i don't know how many of them was hooked to the event and
what are the functions hooked, but i need to make sure that i unwired all of them at once.

I could unwire event handlers if i knew the functions:

button.Click += new EventHandler(OnMyBtnClick); // Wire event handler
....
button.Click -= new EventHandler(OnMyBtnClick); // Unwire event handler

But again, i don't know which/how many event handlers are wired to the event.


Any ideas/comments would be highly appreciated!

Thank you
Andrey
 
Directly no, in large part because you cannot simply set the event to null.

Indirectly, you could make the actual event private and create a property
around it that tracks all of the delegates being added/subtracted to it.

Take the following:

ArrayList delegates = new ArrayList();

private event EventHandler MyRealEvent;

public event EventHandler MyEvent
{
add
{
MyRealEvent += value;
delegates.Add(value);
}

remove
{
MyRealEvent -= value;
delegates.Remove(value);
}
}

public void RemoveAllEvents()
{
foreach(EventHandler eh in delegates)
{
MyRealEvent -= eh;
}
delegates.Clear();
}

In this code, we create a wrapper around MyRealEvent (which is what you
would actually trigger internally), so that anytime something is
added/subtracted to it, a list of those EventHandlers is updated accordingly.
When you finally need to clear out all of the events, simply call
RemoveAllEvents() (poorly named I know) which iterates through the list of
EventHandlers and removes each in turn from the real event.

Brendan
 
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