[Python.NET] System.NullReferenceException
Michael Amrhein
Michael.Amrhein at t-online.de
Wed Oct 29 14:04:11 EST 2003
Hi,
when unregistering an event handler I get an exection:
Python 2.3.2 (#49, Oct 2 2003, 20:02:00) [MSC v.1200 32 bit (Intel)] on
win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import CLR
>>> import CLR.System.Windows.Forms as wf
>>> f=wf.Form()
>>> f
<CLR.System.Windows.Forms.Form object at 0x008FE6D0>
>>> def h(s,a): print s,a
...
>>> f.Click += h
>>> f.Click -= h
Unbehandelte Ausnahme: System.NullReferenceException: Der Objektverweis
wurde nicht auf eine Objektinstanz festgelegt.
at Python.Runtime.EventObject.RemoveEventHandler(IntPtr target,
IntPtr handler)
at Python.Runtime.EventBinding.nb_inplace_subtract(IntPtr ob, IntPtr
arg)
The same happens when I try to call the event.
The demo apps run without any problem; i.e. Python event handlers are
called correctly by the CLR. But trying to unregister the event handler
in helloform.py:
...
WinForms.MessageBox.Show("Please do not press this button again.")
self.button.Click -= self.button_Click
causes the same exception as shown above.
Michael
P.S.: I run CLR v1.1 on Win XP
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