Problem printing element

Expected Behavior

Print out all elements

Actual Behavior

only a small part is printed, an error is thrown;

return bool(IUIA().iuia.CompareElements(self.element, other.element))
_ctypes.COMError: (-2147220991, 'event cannot call any subscribers', (None, None, None, 0, None))

Steps to Reproduce the Problem

1.My automation software is WPF type

Short Example of Code to Demonstrate the Problem

def test(self):
    wd = self.app[u"放射影像软件"]
    wd.print_ctrl_ids(filename="photograph.txt")
if __name__ == '__main__':
    # app = Application(backend='uia').start(r"E:\fs\fs.exe")
    app = Application(backend="uia").connect(handle=0x20C04)
    ph = Photograph(app)
    ph.test()

Specifications

• Pywinauto version: 0.6.7
• Python version and bitness: 3.7.4
• Platform and OS: Windows 10 home

[vasily-v-ryabov]

Sorry, I missed the info that button is really clicked. Well, the exception is raised by UIAutomationCore.dll so the right question is “what Microsoft wants to tell us?”. But this is not an empty implementation. Of course we can handle this kind of error and convert it to RuntimeWarning. But please create separate issue on it. This is completely different to the initial issue.

Sometimes we also face with hang problem when calling .invoke() (.click() is an alias of .invoke() for ButtonWrapper). It means we need to create a separate thread with some timeout and print a warning if it is timed out. This is also separate issue, but we can combine it in one issue since it is all in .invoke() method.

[DiegoQueiroz]

@vasily-v-ryabov I could agree with you, but I still think there’s something wrong with pywinauto. The main reason is because the button is clicked as expected. I could use click_input() but there is no real reason to do so.

I am running my script with the code bellow and it does not present any instability:

app = Application(backend="uia").start(app_path)
try:
  app.AppTitle.Login.click()
except:
  pass

# script continues here

The question is, why pywinauto is raising an exception if it is working as expected? I understand that maybe it detected some bad implementation in the invoke method or something, but since the method is fired, what pywinauto is trying to tell me with this exception? Is there something weird happening that I should be handling?

Got my point? Or there is a good explanation for this, or it is a bug since the exception is useless.

At least, it should catch this exception and provide specific information about the problem, instead of raising a generic COM Error.