我在将一个类实例中定义的变量传递到另一个类实例时遇到问题。我对使用类相对较新，但据我了解，只需将变量定义为类实例的一部分(例如下面的示例)，就可以将变量从一个实例传递到另一个实例。虽然我过去使用过此模型，但从未尝试使用 GUI 框架(例如 wxPython)来执行此操作。
class Foo(object):
def __init__(self, var):
self.var = var
class Bar(object):
def do_something(self, var):
print var*3
if __name__ == '__main__':
f = Foo(3)
b = Bar()
b.do_something(f.var)
我遇到的问题是 wxPython 实例似乎是预定义的，并且不接受任何附加参数(允许我只传递标题、大小等内容)到类实例。
我面临的另一个问题是我试图通过调用对话框窗口将变量传递到三个类深处，并从对话框中调用一个旨在启动工作线程的单独类。
所以我的问题是:
如何将变量从第一个类实例传递到第三个类实例？
如何重写 wxPython 实例以允许定义其他变量？
或者，是否可以创建自定义事件处理程序来传递必要的数据？
为了澄清...
我正在使用 Python，并且希望我了解使用类和 GUI 以及 Tkinter 和 wxPython(在本项目中使用)等框架进行编程的基础知识。我编写了一个主类/实例，它从用户那里获取一些数据，我希望能够传递存储在 self.main_instance_var 中的信息并将其传递给第二个类/实例(在本例中是进度对话框窗口)从头等舱调用。
当我尝试在进度对话框中使用上述模型时，出现了一个非常无信息的语法错误(“关键字 arg 之后非关键字 arg”)。阻止我进一步将变量从进度对话框窗口传递到工作线程。如果我遇到异常，那是一回事，但我不明白语法错误。请看下面的一个简短示例:
class ProgressDialog(wx.Dialog):
def __init__(self, parent, title, myVar): # Generates syntax error on this line
super(ProgressDialog, self).__init__(parent=parent,
title=title, size=(500, 110))
self.var = myVar
基本来源(根据要求，抱歉它太脏了):
import time
import os, sys, wx
from ftplib import FTP_TLS
from threading import Thread
from wx.lib.pubsub import Publisher
########################################################################
class FtpValues(object):
""" Returns a property attribute - called by FtpFileTransfer
Used to set values/variables for Host, USERID, PASSWD, FILE """
#----------------------------------------------------------------------
def __init__(self):
self.varList = None
#----------------------------------------------------------------------
def GetValues(self):
return self.varList
#----------------------------------------------------------------------
def SetValues(self, HOST, USERID, PASSWD, FILE):
self.varList = [HOST, USERID, PASSWD, FILE]
#----------------------------------------------------------------------
def DelValues(self):
del self.valList
Values = property(GetValues, SetValues, DelValues, "Set/Get FtpValues")
# http://docs.python.org/library/functions.html#property
########################################################################
class FtpFileTransfer(Thread):
"""Test Worker Thread Class."""
#----------------------------------------------------------------------
def __init__(self):
"""Init Worker Thread Class."""
Thread.__init__(self)
self.StartTransfer() # start the thread
#----------------------------------------------------------------------
def StartTransfer(self): # was named run - started automatically
"""Run Worker Thread.""" # when called by the start method
# This is the code executing in the new thread.
HOST, USERID, PASSWD, FILE = FtpValues.Values
BLOCKSIZE = 57344
try:
ftp = FTP_TLS(HOST)
ftp.login(USERID, PASSWD)
ftp.prot_p()
ftp.voidcmd("TYPE I")
f = open(FILE, 'rb')
datasock, esize = ftp.ntransfercmd(
'STOR %s' % os.path.basename(FILE))
size = os.stat(FILE)[6]
bytes_so_far = 0
while 1:
buf = f.read(BLOCKSIZE)
if not buf:
break
datasock.sendall(buf)
bytes_so_far += len(buf)
msg = [bytes_so_far, size]
Publisher().sendMessage("update", msg)
except: raise
finally:
try:
datasock.close()
f.close()
ftp.voidresp()
ftp.quit()
print 'Complete...'
except: pass
wx.CallAfter(Publisher().sendMessage, "update", "Database Transfer Complete!")
########################################################################
class ProgressDialog(wx.Dialog):
def __init__(self, parent, title):
super(ProgressDialog, self).__init__(parent=parent,
title=title, size=(500, 110))
self.displayLbl = wx.StaticText(self, -1, 'Verifying Database Files... ', (20, 20)) #Preparing for Transfer...
self.gauge = wx.Gauge(self, -1, 100, (20, 45), (370, 24))
self.btn = btn = wx.Button(self, -1, 'Cancel', (400, 45), (-1, 25))
btn.Bind(wx.EVT_BUTTON, self.OnClose)
# listens for response from worker thread
Publisher().subscribe(self.updateDisplay, "update")
FtpFileTransfer()#.StartTransfer(HOST, USERID, PASSWD, FILE) #Start the FTP Worker Thread
#self.OnStart()
#----------------------------------------------------------------------
def run(self):
FtpFileTransfer(HOST, USERID, PASSWD, FILE)
#----------------------------------------------------------------------
def OnClose(self, event):
""" Place Holder """
if self.btn.GetLabel() == 'Finish':
# Do Something!
pass
return None
#----------------------------------------------------------------------
def updateDisplay(self, msg):
""" Receives data from thread and updates the display """
if isinstance(msg.data, list):
bytes_so_far, size = msg.data
k = 100 * bytes_so_far / size
self.displayLbl.SetLabel("Sent %d of %d bytes %.1f%%" % (bytes_so_far, size, 100 * bytes_so_far / size))
self.gauge.SetValue(k)
else:
self.displayLbl.SetLabel("%s" % msg.data)
#self.btn.Enable()
self.btn.SetLabel('Finish')
########################################################################
class MyForm(wx.Frame):
#----------------------------------------------------------------------
def __init__(self):
wx.Frame.__init__(self, None, wx.ID_ANY, "Tutorial")
# Add a panel so it looks the correct on all platforms
panel = wx.Panel(self, wx.ID_ANY)
self.displayLbl = wx.StaticText(panel, label="Amount of time since thread started goes here")
self.btn = btn = wx.Button(panel, label="Start Thread")
self.gauge = wx.Gauge(panel, -1, 100, size=(370, 24))
btn.Bind(wx.EVT_BUTTON, self.onButton)
sizer = wx.BoxSizer(wx.VERTICAL)
sizer.Add(self.displayLbl, 0, wx.ALL|wx.CENTER, 5)
sizer.Add(btn, 0, wx.ALL|wx.CENTER, 5)
sizer.Add(self.gauge, 0, wx.ALL|wx.CENTER, 5)
panel.SetSizer(sizer)
self.VarData()
# create a pubsub receiver
Publisher().subscribe(self.updateDisplay, "update")
#----------------------------------------------------------------------
def onButton(self, event):
"""
Runs the thread
"""
chgdep = ProgressDialog(None, title='File Transfer. . .')
chgdep.ShowModal()
#chgdep.Destroy()
#----------------------------------------------------------------------
def updateDisplay(self, msg):
"""
Receives data from thread and updates the display
"""
if isinstance(msg.data, list):
bytes_so_far, size = msg.data
k = 100 * bytes_so_far / size
self.displayLbl.SetLabel("Sent %d of %d bytes %.1f%%" % (bytes_so_far, size, 100 * bytes_so_far / size))
self.gauge.SetValue(k)
else:
self.displayLbl.SetLabel("%s" % msg.data)
self.btn.Enable()
#----------------------------------------------------------------------
def VarData(self):
HOST = '127.0.0.1'
USERID = 'test'
PASSWD = 'P@ssw0rd'
FILE = r'F:\Programming\temp\Test.zip'
varList = [HOST, USERID, PASSWD, FILE]
FtpValues.Values = HOST, USERID, PASSWD, FILE
#----------------------------------------------------------------------
# Run the program
if __name__ == "__main__":
app = wx.PySimpleApp()
frame = MyForm().Show()
app.MainLoop()
最佳答案
就我个人而言，我喜欢使用 wx.lib.pubsub 在类之间传递信息。我在我的应用程序中一直这样做。您可以在这里阅读:http://www.blog.pythonlibrary.org/2010/06/27/wxpython-and-pubsub-a-simple-tutorial/
如果你需要从线程发布数据，你将需要使用线程安全的方法，如wx.CallAfter、wx.CallLater或wx.PostEvent。您可以通过在线程安全方法之一内调用 pubsub 发布者来将它们与 pubsub 结合起来。我在这里展示如何做到这一点:http://www.blog.pythonlibrary.org/2010/05/22/wxpython-and-threads/
他们的 wiki 上还有一篇关于线程和 wxPython 的好文章:http://wiki.wxpython.org/LongRunningTasks
关于python - 使用Python将变量从一个类实例传递到另一个类实例？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/8872557/