如何在打开新的Tkinter窗口时运行可取消功能

Question

在tkinter中，我想创建以下内容：

当按下按钮foo时，函数foo立即开始运行。一个新窗口将弹出一个"取消"按钮，用户可以在中途终止流程(因为我的实际流程可能需要30分钟)。如果foo运行到完成，则窗口会自行关闭并通知用户进程已完成。

以下是演示我的玩具问题的代码：

from tkinter import ttk, messagebox, Toplevel, Tk
import time
import multiprocessing
def foo():
for i in range(100):
print(i)
time.sleep(0.1)
class TerminatedProcess(Exception):
def __init__(self, str = "Process was terminated"):
self.error_str = str
class ProcessWindow(Toplevel):
def __init__(self, parent, process):
Toplevel.__init__(self, parent)
self.parent = parent
self. process = process
terminate_button = ttk.Button(self, text="Cancel", command=self.cancel)
terminate_button.grid(row=0, column=0)
self.grab_set() # so you can't push submit multiple times
def cancel(self):
self.process.terminate()
self.destroy()
raise TerminatedProcess
def launch(self):
self.process.start()
self.process.join()
self.destroy()
class MainApplication(ttk.Frame):
def __init__(self, parent, *args, **kwargs):
ttk.Frame.__init__(self, parent, *args, **kwargs)
self.parent = parent
self.button = ttk.Button(self, text = "foo", command = self.callback)
self.button.grid(row = 0, column = 0)
def callback(self):
try:
proc = multiprocessing.Process(target=foo)
process_window = ProcessWindow(self, proc)
process_window.launch()
except TerminatedProcess as e: # raised if foo is cancelled in other window
messagebox.showinfo(title="Cancelled", message=e.error_str)
else:
messagebox.showinfo(message="sucessful run", title="Finished")
def main():
root = Tk()
my_app = MainApplication(root, padding=(4))
my_app.grid(column=0, row=0)
root.mainloop()
if __name__ == '__main__':
main()

有了这段代码，当按下按钮foo时，process_window确实被创建了，因为函数foo运行，我得到了一个"运行成功"对话框，但窗口永远不会弹出！这是一个问题，因为用户需要有终止foo的选项。有趣的是，如果我删除process_window.lonch()，我仍然会收到"运行成功"的消息(正如预期的那样)，但process_window会出现。

我曾尝试将启动命令放入初始化中，但这也使窗口无法显示。

我还尝试在窗口外启动流程，如下所示：

proc.start()
process_window = ProcessWindow(self, proc)
proc.join()

该窗口仍然无法显示，但进程已运行。

我的问题是，我需要如何安排这些片段来生成ProcessWindow，并在ProcessWindow打开时自动启动流程？

UPDATE(解决方法)：我知道我可以在ProcessWindow中创建一个启动按钮来运行该功能(然后在按下一次按钮后禁用该按钮)，但我仍然想知道如何实现原始问题中描述的内容。

Answer 1

也许您正在寻找这样的东西：

from tkinter import ttk, messagebox, Toplevel, Tk
import time
import multiprocessing
def foo():
for i in range(100):
print(i)
time.sleep(0.1)
class ProcessWindow(Toplevel):
def __init__(self, parent, process):
Toplevel.__init__(self, parent)
self.parent = parent
self.process = process
terminate_button = ttk.Button(self, text="Cancel", command=self.cancel)
terminate_button.grid(row=0, column=0)
self.grab_set() # so you can't push submit multiple times
def cancel(self):
self.process.terminate()
self.destroy()
messagebox.showinfo(title="Cancelled", message='Process was terminated')
def launch(self):
self.process.start()
self.after(10, self.isAlive)            # Starting the loop to check when the process is going to end
def isAlive(self):
if self.process.is_alive():                     # Process still running
self.after(100, self.isAlive)               # Going again...
elif self:
# Process finished
messagebox.showinfo(message="sucessful run", title="Finished")
self.destroy()
class MainApplication(ttk.Frame):
def __init__(self, parent, *args, **kwargs):
ttk.Frame.__init__(self, parent, *args, **kwargs)
self.parent = parent
self.button = ttk.Button(self, text = "foo", command = self.callback)
self.button.grid(row = 0, column = 0)
def callback(self):
proc = multiprocessing.Process(target=foo)
process_window = ProcessWindow(self, proc)
process_window.launch()
def main():
root = Tk()
my_app = MainApplication(root, padding=(4))
my_app.grid(column=0, row=0)
root.mainloop()
if __name__ == '__main__':
main()