OpenProcess 在 wait_cpu_usage_lower 中失败

Question

我们正在尝试在特定路径打开资源管理器窗口，然后等待准备就绪。客户端是通过rpyc 操作的，因此堆栈跟踪很奇怪。这有时会发生，但仅在同一个测试中。这个函数 (fileman_item_properties) 用于打开文件属性窗口，它在许多不同的地方都可以正常工作。

    command = f'explorer.exe'
    Timings.slow()

    try:
        Application().start(f'{command} /select,{item}')
        app = Application(backend='uia').connect(path=command)
        app.wait_cpu_usage_lower(threshold=0.5, timeout=60, usage_interval=1.0)

4 Traceback (most recent call last):
265   File "/home/serj/work/mpksoft/te/tests/test_vss_simple.py", line 540, in test_restore_root_share_dirs
266     fileman_restore_item(client, self._share_path, version)
267   File "/home/serj/work/mpksoft/te/lib/host/coreui.py", line 377, in fileman_restore_item
268     host_plugin_load(conn, 'coreui').fileman_restore_item(path, version)
269   File "/home/serj/work/.virtualenvs/te36/lib/python3.6/site-packages/rpyc/core/netref.py", line 240, in __call__
270     return syncreq(_self, consts.HANDLE_CALL, args, kwargs)
271   File "/home/serj/work/.virtualenvs/te36/lib/python3.6/site-packages/rpyc/core/netref.py", line 63, in syncreq
272     return conn.sync_request(handler, proxy, *args)
273   File "/home/serj/work/.virtualenvs/te36/lib/python3.6/site-packages/rpyc/core/protocol.py", line 473, in sync_request
274     return self.async_request(handler, *args, timeout=timeout).value
275   File "/home/serj/work/.virtualenvs/te36/lib/python3.6/site-packages/rpyc/core/async_.py", line 102, in value
276     raise self._obj
277 rpyc.core.vinegar/pywintypes._get_exception_class.<locals>.Derived: (87, 'OpenProcess', 'The parameter is incorrect.')
278 
279 ========= Remote Traceback (1) =========
280 Traceback (most recent call last):
281   File "C:\Program Files\Python38\lib\site-packages\rpyc\core\protocol.py", line 320, in _dispatch_request
282     res = self._HANDLERS[handler](self, *args)
283   File "C:\Program Files\Python38\lib\site-packages\rpyc\core\protocol.py", line 593, in _handle_call
284     return obj(*args, **dict(kwargs))
285   File ".\windows\coreui.py", line 1285, in fileman_restore_item
286     fileman_item_properties(path)
287   File ".\windows\coreui.py", line 422, in fileman_item_properties
288     app.wait_cpu_usage_lower(threshold=0.5, timeout=60, usage_interval=1.0)
289   File "C:\Program Files\Python38\lib\site-packages\pywinauto\application.py", line 1135, in wait_cpu_usage_lower
290     while self.cpu_usage(usage_interval) > threshold:
291   File "C:\Program Files\Python38\lib\site-packages\pywinauto\application.py", line 1110, in cpu_usage
292     h_process = win32api.OpenProcess(win32con.MAXIMUM_ALLOWED, 0, self.process)
293 pywintypes.error: (87, 'OpenProcess', 'The parameter is incorrect.')

UPD

很遗憾，下面的代码没有解决问题。未就绪的进程不知何故通过connect 超时。

      Application().start(f'{command} /select,{item}')
        app = Application(backend='uia').connect(path=command, title_re=f'.*{base_name}.*', timeout=60)
        app.wait_cpu_usage_lower(threshold=0.5, timeout=60, usage_interval=1.0)

顺便说一句，在出错时资源管理器窗口尚未显示。

Answer 1

有时explorer.exe 没有足够的时间开始。您需要为connect() 方法使用显式超时：

app = Application(backend='uia').connect(path=command, timeout=10)

另一种可能的情况是已经存在的explorer.exe 实例已经在运行并且通过可执行文件名连接是间歇性的。那么请使用按标题连接！

app = Application(backend='uia').connect(title="Properties", timeout=10)

Readme.md 中的标准示例也可能有帮助：https://github.com/pywinauto/pywinauto/tree/master#ms-ui-automation-example