python - 如何从主窗口启动 TKinter 进度条

Question

我在创建进度条的方法中有代码:

def progress_bar(self, message = None, icon_path = None, icon_name = None, size = 0, file_location = None, interval = 100):
    #size: in bytes of download
    #file_location: location of the download
    #interval: frequency, in ms, of how often to poll the file for progress
    self.find_icon(icon_path, icon_name)
    self.text_label = tk.Label(text = message)
    self.set_colors(self.text_label)
    self.set_colors(self.image_label)
    self.image_label.grid(row = 1, column = 1, sticky = 'NSEW')
    self.text_label.grid(row = 1, column = 2, sticky = 'NSEW')
    self.progress = ttk.Progressbar(self, orient="horizontal", length=(self.xp/3), mode="determinate")
    self.progress.grid(row = 1, column = 3, sticky = 'NSEW')
    self.progress["value"] = 0
    self.progress["maximum"] = size
    self.auto_resize(1, 3)
    self.progress.start(interval)
    self.after(1, self.check_for_completion(file_location))
    self.mainloop()

def check_for_completion(self, file_location):
    #while (self.progress["value"] < self.progress["maximum"]):
    self.progress["value"] = os.stat(file_location).st_size
    print self.progress["value"]

    if (self.progress["value"] >= self.progress["maximum"]):
        self.text_label = tk.Label(text = message + ": Completed")
        #force a repaint and wait for the user to see it
        self.text_label.grid(row = 1, column = 2)
        time.sleep(30)
        self.choice(True)
        self._delete_window

通过健全性测试，我在同一脚本中有一个 __ main __ 方法，我想做的是创建一个临时文件，启动进度条，然后开始将字符放入临时文件中。不幸的是，我找不到以非阻塞方式启动进度栏的方法。

我尝试像这样使用 python Multiprocessing:

p = Process(target = frame4.progress_bar, kwargs = kwarrgh)
p.start()
p.join()

并且非常生气;)消息说

Break on __THE_PROCESS_HAS_FORKED_AND_YOU_CANNOT_USE_THIS_COREFOUNDATION_FUNCTIONALITY___YOU_MUST_EXEC__() to debug.

注意:本练习的重要部分是从主窗口在后台启动 Tkinter 窗口，而不是相反。我发现了很多关于后者的问题，但没有发现前者。

答案不需要是线程安全的，以防存在有效的多线程而不是多处理方法。

Answer 1

只需使用 after() 继续调用函数 check_for_completion 即可，直到流程完成。

def check_for_completion(self, file_location):
    ... # your code

    if (self.progress["value"] >= self.progress["maximum"]):
        ... # you code 
    else:             # 'value' is not bigger then maximum so we run the function again.
        self.after(10, lambda: self.check_for_completion(file_location))

请注意我如何使用 after 方法来调用带参数的函数。您也应该在您的线路上这样做:

#self.after(1, self.check_for_completion(file_location))  # Not like this
self.after(1, lambda: self.check_for_completion(file_location))  # like this