如何从一个窗口（类）到另一个窗口（类）获取进度条开始（）信息？

Question

有一个带有菜单和进度条的主窗口。带有 OK 按钮的对应窗口在菜单命令时打开，并且 OK 按钮启动该过程（此处：3 秒睡眠）。 通信窗口是通过继承我未在此处提供的类创建的（如果需要回答，请告诉我）。方法apply 和ok 覆盖了母类中的现有方法。

现在我的问题：由于进度条位于主窗口（App 类）中，而progressbar(start) 和progressbar(stop) 在通信窗口中，我不知何故必须通过母类 tkSimpleDialog.Dialog 传递（开始）和（停止）到类 App。所以我想我也重写了__init__(self..)方法，提供self.到进度条。

我怎样才能做到这一点？

import Tkinter, ttk, tkFileDialog, tkSimpleDialog, time, threading

class App:
  def __init__(self, master, progressbar):
    self.progress_line(master)

  def progress_line (self, master):
    self.progressbar = ttk.Progressbar(master, mode='indeterminate')
    self.progressbar.place(anchor = 'ne', height = "20", width = "150", x = "175", y = "30")

class AppMenu(object):

  def __init__(self, master, progressbar):
    self.master = master
    self.menu_bar()

  def menu_bar(self):
    menu_bar = Tkinter.Menu(self.master)
    self.menu_bar = Tkinter.Menu(self.master)
    self.master.config(menu=self.menu_bar)
    self.create_menu = Tkinter.Menu(self.menu_bar, tearoff = False)
    self.create_menu.add_command(label = "do", command = self.do)
    self.menu_bar.add_cascade(label = "now", menu = self.create_menu)

  def do(self):
    do1 = Dialog(self.master, progressbar)    

class Dialog(tkSimpleDialog.Dialog):

  def __init__(self, parent, progressbar):

    tkSimpleDialog.Dialog.__init__(self, parent, progressbar)
    self.transient(parent)

    self.parent = parent
    self.result = None

    self.progressbar = progressbar

    body = Frame(self)
    self.initial_focus = self.body(body)
    body.pack(padx=5, pady=5)

    self.buttonbox()
    self.grab_set()

    if not self.initial_focus:
        self.initial_focus = self

    self.protocol("WM_DELETE_WINDOW", self.cancel)
    self.geometry("+%d+%d" % (parent.winfo_rootx()+50, parent.winfo_rooty()+50))
    self.initial_focus.focus_set()
    self.wait_window(self)

  def ok(self, event=None):
    self.withdraw()
    self.start_foo_thread()
    self.cancel()
  def apply(self):
    time.sleep(5)

  def start_foo_thread(self):
    global foo_thread
    self.foo_thread = threading.Thread(target=self.apply)
    self.foo_thread.daemon = True
    self.progressbar.start()
    self.foo_thread.start()
    master.after(20, check_foo_thread)

  def check_foo_thread(self):
    if self.foo_thread.is_alive():
        root.after(20, self.check_foo_thread)
    else:
        self.progressbar.stop()    

master = Tkinter.Tk()
progressbar = None
app = App(master, progressbar)
appmenu = AppMenu(master, progressbar)
master.mainloop()

错误信息： 先点击ok后：

Exception in Tkinter callback
Traceback (most recent call last):
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk/Tkinter.py", line 1410, in __call__
  File "ask-progressbar.py", line 57, in ok
    self.start_foo_thread()
  File "ask-progressbar.py", line 66, in start_foo_thread
    self.progressbar.start()
AttributeError: Dialog2 instance has no attribute 'progressbar'

秒：关闭应用后

Exception in Tkinter callback
Traceback (most recent call last):
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk/Tkinter.py", line 1410, in __call__
  File "ask-progressbar.py", line 26, in do
    do1 = Dialog2(self.master, progressbar)
  File "ask-progressbar.py", line 33, in __init__
    self.transient(parent)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk/Tkinter.py", line 1652, in wm_transient
TclError: can't invoke "wm" command:  application has been destroyed

Answer 1

以下是您的代码的工作版本。我必须解决许多问题，因为您没有更改代码中的许多内容，而我对您的其他 question 的回答是关于进度条的。

您的主要问题的答案基本上是您必须传递实例并在必要时在所涉及的各种类实例中记住它，以便他们的方法在需要时可以通过self 参数使用它。此外，您尝试派生和覆盖tkSimpleDialog.Dialog 基类方法的方式既过于复杂又不正确。

通常最好（也是最简单）的做法是提供您自己的validate() 和apply() 方法，因为它就是这样设计的。如果您还需要自己的__init__() 构造函数，那么只将参数传递给它从子类中的方法中理解的基类方法很重要。如果您需要更多功能，通常可以通过其他仅派生类方法提供，只有它或您创建的其他类知道。

不管怎样，这就是我最终得到的结果：

import Tkinter, ttk, tkFileDialog, tkSimpleDialog, time, threading

class App:
    def __init__(self, master):
        self.progress_line(master)

    def progress_line(self, master):
        # the value of "maximum" determines how fast progressbar moves
        self._progressbar = ttk.Progressbar(master, mode='indeterminate', 
                                            maximum=4) # speed of progressbar
        self._progressbar.place(anchor='ne', height="20", width="150", 
                                x="175", y="30")
    @property
    def progressbar(self):
        return self._progressbar # return value of private member

class AppMenu(object):
  def __init__(self, master, progressbar):
      self.master = master
      self.menu_bar()
      self.progressbar = progressbar

  def menu_bar(self):
      self.menu_bar = Tkinter.Menu(self.master)
      self.master.config(menu=self.menu_bar)
      self.create_menu = Tkinter.Menu(self.menu_bar, tearoff=False)
      self.create_menu.add_command(label="do", command=self.do)
      self.menu_bar.add_cascade(label="now", menu=self.create_menu)

  def do(self):
      Dialog(self.master, self.progressbar) # display the dialog box

class Dialog(tkSimpleDialog.Dialog):
    def __init__(self, parent, progressbar):
        self.progressbar = progressbar
        tkSimpleDialog.Dialog.__init__(self, parent, title="Do foo?")

    def apply(self):
        self.start_foo_thread()

    # added dialog methods...
    def start_foo_thread(self):
        self.foo_thread = threading.Thread(target=self.foo)
        self.foo_thread.daemon = True
        self.progressbar.start()
        self.foo_thread.start()
        master.after(20, self.check_foo_thread)

    def check_foo_thread(self):
        if self.foo_thread.is_alive():
            master.after(20, self.check_foo_thread)
        else:
            self.progressbar.stop()

    def foo(self): # some time-consuming function...
        time.sleep(3)


master = Tkinter.Tk()
master.title("Foo runner")
app = App(master)
appmenu = AppMenu(master, app.progressbar)
master.mainloop()

希望这会有所帮助。

Answer 2

这是另一个更简单的解决方案，不需要使用线程——因此在您的情况下可能更容易使用/适应。它在耗时的foo() 函数期间多次调用进度条小部件的update_idletasks() 方法。同样，它说明了如何将进度条传递给需要它的代码的各个部分。

import Tkinter, ttk, tkFileDialog, tkSimpleDialog, time

class App:
    def __init__(self, master):
        self.progress_line(master)

    def progress_line(self, master):
        self._progressbar = ttk.Progressbar(master, mode='indeterminate')
        self._progressbar.place(anchor='ne', height="20", width="150", 
                                x="175", y="30")
    @property
    def progressbar(self):
        return self._progressbar # return value of private member

class AppMenu(object):
    def __init__(self, master, progressbar):
        self.master = master
        self.menu_bar()
        self.progressbar = progressbar

    def menu_bar(self):
        self.menu_bar = Tkinter.Menu(self.master)
        self.master.config(menu=self.menu_bar)
        self.create_menu = Tkinter.Menu(self.menu_bar, tearoff=False)
        self.create_menu.add_command(label="do foo", command=self.do_foo)
        self.menu_bar.add_cascade(label="now", menu=self.create_menu)

    def do_foo(self):
        confirm = ConfirmationDialog(self.master, title="Do foo?")
        self.master.update() # needed to completely remove conf dialog
        if confirm.choice:
            foo(self.progressbar)

class ConfirmationDialog(tkSimpleDialog.Dialog):
    def __init__(self, parent, title=None):
        self.choice = False
        tkSimpleDialog.Dialog.__init__(self, parent, title=title)

    def apply(self):
        self.choice = True

def foo(progressbar):
    progressbar.start()
    for _ in range(50):
        time.sleep(.1) # simulate some work
        progressbar.step(10)
        progressbar.update_idletasks()
    progressbar.stop()

master = Tkinter.Tk()
master.title("Foo runner")
app = App(master)
appmenu = AppMenu(master, app.progressbar)
master.mainloop()