How to remove all Event handler from a Control in C#.net

Question

I am using some recursive function during my form load. I am attaching event handlers on controls programmatically. Due to recursive function, event handlers get hooked multiple times to a control. I want to remove all handlers from these controls.

Eg. I have added keypress, keydown, gotfocus etc. events in a textbox. I want to remove all these handlers. How do achieve it ?

Possible duplicate of: http://stackoverflow.com/questions/91778/how-to-remove-all-event-handlers-from-a-control — Dave Zych, Oct 03 '12 at 17:49
well it removes only the click event. I want to remove all the events from a control. How do I do it ? — Nitin Kabra, Oct 03 '12 at 17:51
It sounds like the multiple handlers was not intended... Wouldn't it be better to just keep from adding multiple handlers in the first place? — Andrew Barber, Oct 03 '12 at 17:57
I want to add it once, not more than that. i.e. keypress, keydown, gotfocus all these once. but due to some function calls these are getting added more than once. — Nitin Kabra, Oct 03 '12 at 18:00
the method private void RemoveClickEvent(Button b) in this post http://stackoverflow.com/questions/91778/how-to-remove-all-event-handlers-from-a-control does the job, but it only removes the click event. — Nitin Kabra, Oct 03 '12 at 18:03

score 1 · Answer 1 · answered Oct 03 '12 at 17:51

1

if loEventHandler is an event handler you've previously subscribed to an event (Click, for example), you can remove it by doing loBox.Click -= loEventHandler;.

Events can also be cleared within the private scope by setting the event to null MyEvent = null; That doesn't work for the public scope, though.

answered Oct 03 '12 at 17:51

Sheridan Bulger

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I am looking to remove all events. It can be messy if I add more handlers, more than 5,6. so I want to remove all at once. – Nitin Kabra Oct 03 '12 at 17:53

score 0 · Answer 2 · answered Oct 03 '12 at 18:00

0

You can't do it from the "outside" world since events are special kinds of delegates which don't allow subscribers to interfere between each other.

answered Oct 03 '12 at 18:00

BlackBear

22,411
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the method private void RemoveClickEvent(Button b) in this post http://stackoverflow.com/questions/91778/how-to-remove-all-event-handlers-from-a-control does the job, but it only removes the click event. – Nitin Kabra Oct 03 '12 at 18:02
@NitinKabra: Well, that's kind of an hacky way to get the job done ;) – BlackBear Oct 03 '12 at 18:08
Ah. Hacky reflection. I suppose it works, just substitute the event you want to use for `Click` – Sheridan Bulger Oct 03 '12 at 18:16

score 0 · Answer 3 · answered Oct 03 '12 at 19:05

To avoid a single event being registered multiple times , you can add a property wrapper like this

    public event EventHandler<EventArgs> _event;
    public event EventHandler<EventArgs> PublicEvent
    {

        add
        {
            if (_event == null)
                _event += value;
        }

        remove
        {
            _event -= value;
        }
    }

How to remove all Event handler from a Control in C#.net

3 Answers3