這是一個簡單的圖形用戶界面。我正在從條目中的用戶那里獲取 url。當按下按鈕時，url被保存在一個檔案中，并呼叫另一個函式通過呼叫（在子行程內）啟動另一個行程。在行程運行時，我想顯示不確定的進度條（直到按下按鈕，該條需要隱藏），當行程完成時，會顯示一條 showinfo 訊息以銷毀 gui。
問題：直到程序完成，該欄才會顯示。顯示 showinfo 對話框后，它才開始進行。意味著，酒吧在它應該真正被摧毀的那一刻開始進步。
我的代碼有什么問題？
import scrapy
import tkinter as tk
from tkinter import messagebox as tkms
from tkinter import ttk
import shlex
from subprocess import call
def get_url():
# get value from entry and write to a file
def scrape():
progress_bar = ttk.Progressbar(root, orient=tk.HORIZONTAL, length=300, mode='indeterminate')
progress_bar.grid(row=3, column=2)
progress_bar.start(10)
command_line = shlex.split('scrapy runspider /media/mayank/Local/Coding/Lab/Scraping/Practices/img.py')
call(command_line)
mes = tkms.showinfo(title='progress', message='Scraping Done')
if mes == 'ok':
root.destroy()
root = tk.Tk()
root.title("Title")
entry1 = tk.Entry(root, width=90, textvariable=url)
entry1.grid(row=0, column=0, columnspan=3)
my_button = tk.Button(root, text="Process", command=lambda: [get_url(), scrape()])
my_button.grid(row=2, column=2)
root.mainloop()
----更新代碼---
import scrapy
import tkinter as tk
from tkinter import messagebox as tkms
from tkinter import ttk
import shlex
from subprocess import call
def get_url():
# get value from entry and write to a file
scrapy = None
def watch():
global scrapy
if scrapy:
if scrapy.poll() != None:
# Update your progressbar to finished.
progress_bar.stop()
progress_bar.destroy()
# Maybe report scrapy.returncode?
print(f'scrapy return code =--######==== {scrapy.returncode}')
scrapy = None
else:
# indicate that process is running.
progress_bar.start(10)
print(f'scrapy return code =--######==== {scrapy.returncode}')
# Re-schedule `watch` to be called again after 0.1 s.
root.after(100, watch)
def scrape():
global scrapy
command_line = shlex.split('scrapy runspider ./img.py')
scrapy = Popen(command_line)
watch()
mes = tkms.showinfo(title='progress', message='Scraping Done')
if mes == 'ok':
root.destroy()
root = tk.Tk()
root.title("Title")
url = tk.StringVar(root)
entry1 = tk.Entry(root, width=90, textvariable=url)
entry1.grid(row=0, column=0, columnspan=3)
my_button = tk.Button(root, text="Process", command=lambda: [get_url(), scrape()])
my_button.grid(row=2, column=2)
progress_bar = ttk.Progressbar(root, orient=tk.HORIZONTAL, length=300, mode='indeterminate')
progress_bar.grid(row=3, column=2)
root.mainloop()
uj5u.com熱心網友回復：
Using會subprocess.call 中斷當前行程，直到被呼叫的行程完成。因此，在呼叫完成之前，GUI 不會更新。
重要提示： 切勿從程式的主執行緒呼叫 或其他便利函式subprocess.run之一。這樣做會凍結 GUI。您應該只從主執行緒創建物件。subprocess.calltkintersubprocess.Popen
您應該做的是創建一個Popen物件，同時禁用開始按鈕。
要跟蹤進度，請定義一個定期呼叫的函式root.after()，例如每 0.1 秒。在此函式中，您可以呼叫該poll()方法來檢查子行程是否已完成。或者，您可以從物件的屬性中設定stdout=subprocess.PIPE和讀取來自子行程的資料。stdoutPopen
下面的代碼是基于您更新的問題的作業（對我而言）示例。請注意，我已scrapy在我的 UNIX 機器上用相對長時間運行的命令替換（我沒有）。由于您將 scrapy 作為子行程運行，因此您不需要import scrapy.
import tkinter as tk
from tkinter import messagebox as tkms
from tkinter import ttk
from subprocess import Popen
proc = None
def watch():
global proc
if proc:
if proc.poll() is not None:
# Update your progressbar to finished.
progress_bar.stop()
progress_bar.destroy()
# Maybe report proc.returncode?
print(f'proc return code =--######==== {proc.returncode}')
proc = None
mes = tkms.showinfo(title='progress', message='Scraping Done')
if mes == 'ok':
root.destroy()
else:
# indicate that process is running.
progress_bar.start(10)
# print(f'proc return code =--######==== {proc.returncode}')
# Re-schedule `watch` to be called again after 0.1 s.
root.after(100, watch)
def scrape():
global proc
command_line = ['netstat']
proc = Popen(command_line)
watch()
root = tk.Tk()
root.title("Title")
url = tk.StringVar(root)
entry1 = tk.Entry(root, width=90, textvariable=url)
entry1.grid(row=0, column=0, columnspan=3)
my_button = tk.Button(root, text="Process", command=lambda: [get_url(), scrape()])
my_button.grid(row=2, column=2)
progress_bar = ttk.Progressbar(root, orient=tk.HORIZONTAL, length=300, mode='indeterminate')
progress_bar.grid(row=3, column=2)
root.mainloop()
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