[IronPython] Issues with methods as event handlers?

[Giles Thomas]

Dino,

That makes sense, thanks for the clarification.


Regards,

Giles
-- 
Giles Thomas
Resolver Systems
giles.thomas at resolversystems.com
We're hiring! http://www.resolversystems.com/jobs/

Dino Viehland wrote:
> Another option that should work is:
> 
> class ClickListener:
> 	def trigger(self, source, args):
> 		print "..."
> 
> a = ClickListener()
> b = a.trigger
> 
> triggerButton.Click += b
> 
> triggerButton.Click -= b
> 
> 
> What you're experiencing is the fact that trigger is actually just a callable object.  When you do a.trigger you get a new bound method object that is different from the bound method object you get back when you do the -=.
> 
> We should see if there's a way for us to fix this to match expecations so I'll go ahead and make sure we get the bug filed.
> 
> 
> -----Original Message-----
> From: users-bounces at lists.ironpython.com [mailto:users-bounces at lists.ironpython.com] On Behalf Of Giles Thomas
> Sent: Wednesday, February 01, 2006 11:10 AM
> To: Discussion of IronPython
> Subject: [IronPython] Issues with methods as event handlers?
> 
> Hi all,
> 
> When we use bound methods as Windows Forms event handlers, we can't 
> detach them.  Functions work OK.
> 
> To see the problem, run up the attached button_method.py using 
> IronPythonConsole; if you click on the "Trigger" button, you'll see a 
> log message in the console saying that the trigger method has been 
> called.  Click on the "Remove" button to remove the event handler, and 
> then click on the "Trigger" button again - you'll still get the log 
> message.  So the event handler was not detached correctly.
> 
> By contrast, if you do the same thing using button_function.py, you will 
> see that once you have clicked on "Remove", the "Trigger" button's 
> handler will be correctly detached, so further clicks on that button 
> will not generate log messages.
> 
> We've tested against beta 2, beta 1, and 0.9.5 (which latter doesn't 
> display the button labels but otherwise behaves as described above).
> 
> Hope this helps someone :-)
> 
> 
> Cheers,
> 
> Giles