is it possible to workaround this non-implemented feature by using ___setattr__() hook? seems like people were able to do this in ironpython:
http://stackoverflow.com/questions/3856905/ On Sun, Apr 3, 2016 at 10:40 AM, Tony Roberts <t...@pyxll.com> wrote: > Yeah, it looks like the crash is probably because of the missing event > implementation as suspected. I'm a bit surprised that it didn't fail > earlier when trying to instantiate the type. > > If you do get a chance to take a look at adding that functionality be sure > to submit a pull request! > > Best regards, > Tony > > > On Sun, Apr 3, 2016 at 4:30 PM Hansong Huang <hhsp...@live.com> wrote: > >> Tony, >> >> thanks for the hint. >> >> the event PropertyChanged was declared in INotifyPropertyChanged >> interface by pythonnet, but obviously not implemented. >> [('PropertyChanged', <unbound event 'PropertyChanged'>), >> >> anyway, the stackoverflow only happens if both following are present >> 1. the class is derived from INotifyPropertyChanged interface >> 2. the class exposes property back to .Net vis @clrproperty >> >> which seems to prove that it is the PropertyChanged event that is not >> implemented in python class resulted in the crash. >> >> I was not sure if .Net event can be handled by pythonnet. I found a few >> examples with IronPython, but there, a python class of "event" seems to be >> implemented instead. >> >> Below is the stack trace >> >> >> [External Code] >> clr.dll!CallDescrWorkerInternal () Unknown >> clr.dll!CallDescrWorkerWithHandler(struct CallDescrData *,int) Unknown >> clr.dll!CallDescrWorkerReflectionWrapper(struct CallDescrData *,class >> Frame *) Unknown >> clr.dll!RuntimeMethodHandle::InvokeMethod(class Object *,class >> PtrArray *,class SignatureNative *,bool) Unknown >> mscorlib.ni.dll!00007fffb86e1ca4() Unknown >> mscorlib.ni.dll!00007fffb8618272() Unknown >> mscorlib.ni.dll!00007fffb867fc4a() Unknown >> [External Code] >> mscorlib.ni.dll!00007fffb86dbaf5() Unknown >> mscorlib.ni.dll!00007fffb86d281f() Unknown >> System.ni.dll!00007fffb77556d4() Unknown >> System.ni.dll!00007fffb7755637() Unknown >> System.ni.dll!00007fffb775541d() Unknown >> PresentationFramework.ni.dll!00007fff96c1ca70() Unknown >> PresentationFramework.ni.dll!00007fff96c23902() Unknown >> PresentationFramework.ni.dll!00007fff96c22ea1() Unknown >> PresentationFramework.ni.dll!00007fff96c22693() Unknown >> PresentationFramework.ni.dll!00007fff96c223c9() Unknown >> PresentationFramework.ni.dll!00007fff96c21a03() Unknown >> PresentationFramework.ni.dll!00007fff96c0d84c() Unknown >> PresentationFramework.ni.dll!00007fff96b97299() Unknown >> PresentationFramework.ni.dll!00007fff96b9720e() Unknown >> PresentationFramework.ni.dll!00007fff96c852f0() Unknown >> WindowsBase.ni.dll!00007fff9f6f9bc9() Unknown >> WindowsBase.ni.dll!00007fff9f6f9ac6() Unknown >> WindowsBase.ni.dll!00007fff9f6fca2b() Unknown >> mscorlib.ni.dll!00007fffb86ca79e() Unknown >> mscorlib.ni.dll!00007fffb86ca637() Unknown >> mscorlib.ni.dll!00007fffb86ca5f2() Unknown >> WindowsBase.ni.dll!00007fff9f913810() Unknown >> WindowsBase.ni.dll!00007fff9f6fc784() Unknown >> WindowsBase.ni.dll!00007fff9f6f7c24() Unknown >> WindowsBase.ni.dll!00007fff9f6f8061() Unknown >> WindowsBase.ni.dll!00007fff9f6f9e53() Unknown >> WindowsBase.ni.dll!00007fff9f6f9d82() Unknown >> WindowsBase.ni.dll!00007fff9f6f9bc9() Unknown >> WindowsBase.ni.dll!00007fff9f6f9ac6() Unknown >> WindowsBase.ni.dll!00007fff9f6f7583() Unknown >> WindowsBase.ni.dll!00007fff9f6f94ff() Unknown >> WindowsBase.ni.dll!00007fff9f8c496a() Unknown >> clr.dll!UMThunkStub () Unknown >> user32.dll!UserCallWinProcCheckWow() Unknown >> user32.dll!DispatchMessageWorker() Unknown >> WindowsBase.ni.dll!00007fff9f730ee8() Unknown >> WindowsBase.ni.dll!00007fff9f70d8fc() Unknown >> PresentationFramework.ni.dll!00007fff96af98b3() Unknown >> PresentationFramework.ni.dll!00007fff96af969d() Unknown >> clr.dll!CallDescrWorkerInternal () Unknown >> clr.dll!CallDescrWorkerWithHandler(struct CallDescrData *,int) Unknown >> clr.dll!CallDescrWorkerReflectionWrapper(struct CallDescrData *,class >> Frame *) Unknown >> clr.dll!RuntimeMethodHandle::InvokeMethod(class Object *,class >> PtrArray *,class SignatureNative *,bool) Unknown >> mscorlib.ni.dll!00007fffb86e1c20() Unknown >> mscorlib.ni.dll!00007fffb8618272() Unknown >> [External Code] >> clr.dll!UMThunkStub () Unknown >> [External Code] >> > WPFPy.py!threadStart Line 256 Python >> [External Code] >> >> >> ------------------------------ >> From: t...@pyxll.com >> Date: Sun, 3 Apr 2016 15:20:47 +0000 >> Subject: Re: [Python.NET] How to handle INotifyPropertyChanged interface >> To: hhsp...@pine.cc; pythondotnet@python.org >> >> >> What's the full stack trace? >> >> I suspect it's something to do with the event declared on the interface >> not being implemented. The managed type constructed doesn't define any >> events, so that would cause the construction of the type of fail - which is >> probably the error you're getting (although without the stack trace it's >> just an educated guess). >> >> It shouldn't be too hard to add events to the derived type if someone >> wanted to have a go at implementing it. The code is in the >> CreateDerivedType method in src/runtime/classderived.cs. To be consistent >> with how methods and properties work, it would need a clrevent function >> adding to the clr module (src/runtime/resource/clr.py) - maybe it could >> work like this: >> >> class MyClass(INotifyPropertyChanged): >> OnPropertyChanged = clr.clrevent(event_attributes, event_type) >> >> Then in classderived.cs the class any clrevents on the python class could >> be added to the managed type using TypeBuilder.DefineEvent. >> >> So, anyway - short answer is that what you're trying to do won't work >> without changes to pythonnet; but the changes required shouldn't be too >> hard if you wanted to have a go. >> >> Best regards, >> Tony >> >> >> On Sun, Apr 3, 2016 at 3:37 PM Hansong Huang <hhsp...@live.com> wrote: >> >> It seems inheriting from INotifyPropertyChanged is the cause >> >> self.window = System.Windows.Markup.XamlReader.Load(outStream) >> self.window.DataContext = MyViewModel() >> class MyViewModel(System.Object): >> __namespace__ = "WPFPyDemo" >> def __init__(self): >> super(MyViewModel,self).__init__() >> self._inputText = "Line - in" >> @clr.clrproperty(str) >> def inputText(self): >> return self._inputText >> @inputText.setter >> def inputText(self,value): >> self._inputText = value >> self.OnPropertyChanged("inputText") >> >> The above code works fine. >> >> but if switch inheritance to >> class MyViewModel(System.ComponentModel.INotifyPropertyChanged): >> and nothing else changed, python gives >> >> "The process terminates due to StackOverflowException" >> >> Not sure why. >> >> >> Thanks for the help >> >> ------------------------------ >> From: hhsp...@live.com >> To: pythondotnet@python.org >> Subject: How to handle INotifyPropertyChanged interface >> Date: Thu, 31 Mar 2016 20:38:38 -0400 >> >> >> I am still trying to figure out how to implement WPF MVVM with Python.Net. >> Previously, I have successfully used System.Dynamic.ExpandoObject as a >> ViewModel container >> >> self.window = System.Windows.Markup.XamlReader.Load(outStream) >> self.window.DataContext = DotNetExpandoObject() >> >> where DotNetExpandoObject is a wrapper class for >> System.Dynamic.ExpandoObject >> class DotNetExpandoObject(System.Dynamic.ExpandoObject): >> ... in which I redefined __getattr__ and __setattr__ >> >> it works flawlessly as System.Dynamic.ExpandoObject implements >> INotifyPropertyChange interface already >> >> Now, I would like to get away from using System.Dynamic.ExpandoObject but >> to implement my own >> >> I first tried to expose a python class back to .Net >> class MyViewModel(System.Object): >> __namespace__ = "WPFPyDemo" >> def __init__(self): >> super(MyViewModel,self).__init__() >> self._inputText = "Line - in" >> @clr.clrproperty(str) >> def inputText(self): >> return self._inputText >> @inputText.setter >> def inputText(self,value): >> self._inputText = value >> self.OnPropertyChanged("inputText") >> >> self.window.DataContext = MyViewModel() >> >> The one direction data binding works fine, and the "Line - in" text >> correctly shows up in the textblock control. >> obviously this is not sufficient as there is no INotifyPropertyChange >> interface. >> >> So, I inherit the interface , and tries to implement the typical C# code >> " public event PropertyChangedEventHandler PropertyChanged" >> >> -- not sure how to handle event in Python.Net, the follow code probably >> is completely wrong >> >> class ViewModel(System.ComponentModel.INotifyPropertyChanged): >> __namespace__ = "WPFPy" >> def __init__(self): >> super(ViewModel, self).__init__() >> self.PropertyChanged = >> System.ComponentModel.PropertyChangedEventHandler >> def OnPropertyChanged(self, propertyName): >> if self.PropertyChanged != None: >> PropertyChanged(self, >> System.ComponentModel.PropertyChangedEventArgs(propertyName)) >> >> class MyViewModel(ViewModel): >> __namespace__ = "WPFPyDemo" >> def __init__(self): >> super(MyViewModel,self).__init__() >> self._inputText = "Line - in" >> >> @clr.clrproperty(str) >> def inputText(self): >> return self._inputText >> @inputText.setter >> def inputText(self,value): >> self._inputText = value >> self.OnPropertyChanged("inputText") >> >> >> The process terminates due to StackOverflowException. >> Looks like the error happens when WFP recoganized INotifyPropertyChange >> interface and tries to access MyViewModel class via it. >> _________________________________________________ >> Python.NET mailing list - PythonDotNet@python.org >> https://mail.python.org/mailman/listinfo/pythondotnet >> >> > _________________________________________________ > Python.NET mailing list - PythonDotNet@python.org > https://mail.python.org/mailman/listinfo/pythondotnet >
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