我想在使用urllib.urlretrive方法从网上下载文件时显示进度条。
如何使用ttk.Progressbar执行此任务？
这是我到目前为止所做的：
from tkinter import ttk
from tkinter import *
root = Tk()
pb = ttk.Progressbar(root, orient="horizontal", length=200, mode="determinate")
pb.pack()
pb.start()
root.mainloop()
但它只是不断循环。
答案 0 :(得分：30)
对于确定模式，您不想拨打start。相反，只需配置小部件的value或调用step方法。
如果您事先知道要下载的字节数（我假设您使用的是确定模式），最简单的方法是将maxvalue选项设置为您的数字去读。然后，每次读取块时，将value配置为读取的总字节数。然后进度条将计算百分比。
这是一个模拟，可以给你一个粗略的想法：
import tkinter as tk
from tkinter import ttk
class SampleApp(tk.Tk):
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs)
self.button = ttk.Button(text="start", command=self.start)
self.button.pack()
self.progress = ttk.Progressbar(self, orient="horizontal",
length=200, mode="determinate")
self.progress.pack()
self.bytes = 0
self.maxbytes = 0
def start(self):
self.progress["value"] = 0
self.maxbytes = 50000
self.progress["maximum"] = 50000
self.read_bytes()
def read_bytes(self):
'''simulate reading 500 bytes; update progress bar'''
self.bytes += 500
self.progress["value"] = self.bytes
if self.bytes < self.maxbytes:
# read more bytes after 100 ms
self.after(100, self.read_bytes)
app = SampleApp()
app.mainloop()
为此，您需要确保不阻止GUI线程。这意味着你要么读取块（如示例中所示），要么在单独的线程中读取。如果使用线程，则无法直接调用progressbar方法，因为tkinter是单线程的。
您可能会发现progressbar example上的tkdocs.com有用。
答案 1 :(得分：7)
我为你简化了代码。
import sys
import ttk
from Tkinter import *
mGui = Tk()
mGui.geometry('450x450')
mGui.title('Hanix Downloader')
mpb = ttk.Progressbar(mGui,orient ="horizontal",length = 200, mode ="determinate")
mpb.pack()
mpb["maximum"] = 100
mpb["value"] = 50
mGui.mainloop()
将 50 替换为下载百分比。
答案 2 :(得分：3)
如果您只想要一个进度条来显示程序正忙/工作只需将模式从确定更改为不确定
pb = ttk.Progressbar(root,orient ="horizontal",length = 200, mode ="indeterminate")
答案 3 :(得分：1)
这是另一个简单示例，也显示了进度条的移动。 （我简化了https://gist.github.com/kochie/9f0b60384ccc1ab434eb）
中给出的例子import Tkinter
import ttk
root = Tkinter.Tk()
pb = ttk.Progressbar(root, orient='horizontal', mode='determinate')
pb.pack(expand=True, fill=Tkinter.BOTH, side=Tkinter.TOP)
pb.start(50)
root.mainloop()
答案 4 :(得分：1)
带有进度条的模态对话框窗口，用于更大的项目
这个例子有点长，但是在Python 3.6上测试过，可以在更大的项目中使用。
# -*- coding: utf-8 -*-
# Modal dialog window with Progressbar for the bigger project
import time
import tkinter as tk
from tkinter import ttk
from tkinter import simpledialog
class MainGUI(ttk.Frame):
''' Main GUI window '''
def __init__(self, master):
''' Init main window '''
ttk.Frame.__init__(self, master=master)
self.master.title('Main GUI')
self.master.geometry('300x200')
self.lst = [
'Bushes01.png', 'Bushes02.png', 'Bushes03.png', 'Bushes04.png', 'Bushes05.png',
'Forest01.png', 'Forest02.png', 'Forest03.png', 'Forest04.png', 'Road01.png',
'Road02.png', 'Road03.png', 'Lake01.png', 'Lake02.png', 'Field01.png']
b = ttk.Button(self.master, text='Start', command=self.start_progress)
b.pack()
b.focus_set()
def start_progress(self):
''' Open modal window '''
s = ProgressWindow(self, 'MyTest', self.lst) # create progress window
self.master.wait_window(s) # display the window and wait for it to close
class ProgressWindow(simpledialog.Dialog):
def __init__(self, parent, name, lst):
''' Init progress window '''
tk.Toplevel.__init__(self, master=parent)
self.name = name
self.lst = lst
self.length = 400
#
self.create_window()
self.create_widgets()
def create_window(self):
''' Create progress window '''
self.focus_set() # set focus on the ProgressWindow
self.grab_set() # make a modal window, so all events go to the ProgressWindow
self.transient(self.master) # show only one window in the task bar
#
self.title(u'Calculate something for {}'.format(self.name))
self.resizable(False, False) # window is not resizable
# self.close gets fired when the window is destroyed
self.protocol(u'WM_DELETE_WINDOW', self.close)
# Set proper position over the parent window
dx = (self.master.master.winfo_width() >> 1) - (self.length >> 1)
dy = (self.master.master.winfo_height() >> 1) - 50
self.geometry(u'+{x}+{y}'.format(x = self.master.winfo_rootx() + dx,
y = self.master.winfo_rooty() + dy))
self.bind(u'<Escape>', self.close) # cancel progress when <Escape> key is pressed
def create_widgets(self):
''' Widgets for progress window are created here '''
self.var1 = tk.StringVar()
self.var2 = tk.StringVar()
self.num = tk.IntVar()
self.maximum = len(self.lst)
self.tmp_str = ' / ' + str(self.maximum)
#
# pady=(0,5) means margin 5 pixels to bottom and 0 to top
ttk.Label(self, textvariable=self.var1).pack(anchor='w', padx=2)
self.progress = ttk.Progressbar(self, maximum=self.maximum, orient='horizontal',
length=self.length, variable=self.num, mode='determinate')
self.progress.pack(padx=2, pady=2)
ttk.Label(self, textvariable=self.var2).pack(side='left', padx=2)
ttk.Button(self, text='Cancel', command=self.close).pack(anchor='e', padx=1, pady=(0, 1))
#
self.next()
def next(self):
''' Take next file from the list and do something with it '''
n = self.num.get()
self.do_something_with_file(n+1, self.lst[n]) # some useful operation
self.var1.set('File name: ' + self.lst[n])
n += 1
self.var2.set(str(n) + self.tmp_str)
self.num.set(n)
if n < self.maximum:
self.after(500, self.next) # call itself after some time
else:
self.close() # close window
def do_something_with_file(self, number, name):
print(number, name)
def close(self, event=None):
''' Close progress window '''
if self.progress['value'] == self.maximum:
print('Ok: process finished successfully')
else:
print('Cancel: process is cancelled')
self.master.focus_set() # put focus back to the parent window
self.destroy() # destroy progress window
root = tk.Tk()
feedback = MainGUI(root)
root.mainloop()
答案 5 :(得分：-2)
我想指出一些模拟中不明显的东西。在某些操作系统上，如果打开一个空文件进行写入，os.stat（）将返回0，直到文件句柄关闭。这将使进度条显示下载文件的进度大小失败。