每次用户点击下载按钮时如何创建一个新线程
How to create a new thread each time the user hits the download button
我是 python 的新手，我正在 python 使用 tkinter 和 urllib 创建这个应用程序。基本上，程序获取文件的 URL、名称、格式和路径，然后在用户点击“下载”按钮时下载文件。问题是没有线程程序会冻结，直到下载完成，我不希望这种情况发生。所以经过一些研究，我发现线程可以帮助解决这个问题。使用线程后，我发现我只能启动一个线程一次，这意味着用户只能下载一个 file.So 我发现为了让用户一次下载多个文件，只要用户点击下载按钮程序应该为该下载创建一个新线程，这甚至使用户能够一次下载多个文件。问题是我不知道如何编写这个算法。如果有人帮助我，我将非常感激。
我的代码没有线程：
from tkinter import *
from tkinter import font as tkFont
import random
import urllib.request
import requests
import wget
def printsth():
print("Yay it works! ")
def main_menu():
root = Tk()
root.title('8-bit downloader ')
root.iconbitmap(r"C:\Users\rayanravesh\PycharmProjects\GUI_Calculator\icon.ico")
root.geometry("600x300")
# the top menu
num = IntVar()
chum = IntVar()
var = IntVar()
menu = Menu(root)
root.config(menu=menu)
submenu = Menu(menu)
menu.add_cascade(label="Settings", menu=submenu)
def custom_op():
custom = Toplevel()
custom.iconbitmap(r"C:\Users\rayanravesh\PycharmProjects\GUI_Calculator\icon.ico")
submenu.add_command(label="Customization ", command=custom_op)
def settings_op():
global gps
set_win = Toplevel()
set_win.iconbitmap(r"C:\Users\rayanravesh\PycharmProjects\GUI_Calculator\icon.ico")
path_label = Label(set_win, text="Current default download path: ")
path_entry = Entry(set_win, width=30)
file_read = open('Data.txt', 'r')
data_base = file_read.read()
path_entry.insert(0, data_base)
file_read.close()
def default_output():
global location
file_read2 = open('Data.txt', 'r+')
file_read2.truncate(0)
file_read2.close()
write_file2 = open('Data.txt', 'w')
write_file2.write(path_entry.get())
write_file2.close()
location = path_entry.get() + "\"
default_location = location.replace("\", "\\")
path_btn = Button(set_win, text="Submit ", command=default_output)
path_label.pack(anchor=CENTER, expand=1)
path_entry.pack(anchor=CENTER, expand=1)
path_btn.pack(anchor=CENTER, expand=1)
submenu.add_command(label="Settings ", command=settings_op)
submenu.add_separator()
submenu.add_command(label="Exit", command=root.destroy)
# the section menu
editmenu = Menu(menu)
menu.add_cascade(label="Sections(soon)", menu=editmenu)
editmenu.add_command(label="Downloader", command=printsth)
editmenu.add_command(label="Converter", command=printsth)
editmenu.add_command(label="Media Player", command=printsth)
editmenu.add_command(label="Editor", command=printsth)
# the tool bar
toolbar = Frame(root, bg="light gray")
insert_button = Button(toolbar, text="Insert an image", command=printsth)
insert_button.pack(side=LEFT, padx=2, pady=2)
print_button = Button(toolbar, text="Print", command=printsth)
print_button.pack(side=LEFT, padx=2, pady=2)
toolbar.pack(side=TOP, fill=X)
# the download function
def download_image():
global formatname
if num.get() == 1:
name = random.randrange(1, 1000000)
else:
name = str(name_entry.get())
formatname = str(format_entry.get())
if var.get() == 1:
operator = str(url_entry.get())
formatname = '.' + operator[-3] + operator[-2] + operator[-1]
else:
pass
fullname = str(name) + formatname
url = str(url_entry.get())
fw = open('file-size.txt', 'w')
file_size = int(requests.head(url, headers={'accept-encoding': ''}).headers['Content-Length'])
fw.write(str(file_size))
fw.close()
path = str(output_entry.get()) + "\"
if chum.get() == 1:
filee = open('Data.txt', 'r')
destination = filee.read()
path = destination + "\"
output_entry.insert(0, destination)
filee.close()
else:
output_entry.delete(0, END)
urllib.request.urlretrieve(url, path.replace("\", "\\") + fullname)
# the status bar
status_bar = Label(root, text="Downloading...", bd=1, relief=SUNKEN, anchor=W)
status_bar.pack(side=BOTTOM, fill=X)
# the download frame
body_frame = Frame(root, bg="light blue")
download_button = Button(body_frame, text="Download! ", command=download_image, border=3, width=20, height=5)
download_design = tkFont.Font(size=12, slant='italic')
download_button['font'] = download_design
download_button.pack(side=LEFT, pady=5, padx=5)
body_frame.pack(side=LEFT, fill=Y)
# the main interaction menu
inter_frame = Frame(root)
url_entry = Entry(inter_frame, width=30)
label = Label(inter_frame, text="Enter the image URL: ")
file_format = Label(inter_frame, text="Choose your file format: ")
format_entry = Entry(inter_frame, width=30)
file_name = Label(inter_frame, text="File's name: ")
name_entry = Entry(inter_frame, width=30)
check_name = Checkbutton(inter_frame, text="Give a random name", variable=num)
check_format = Checkbutton(inter_frame, text="Download with default format", variable=var)
check_default = Checkbutton(inter_frame, text="Download to default path", variable=chum)
check_default.deselect()
output_path = Label(inter_frame, text="Choose output path: ")
output_entry = Entry(inter_frame, width=30)
file_name.pack(anchor=CENTER, expand=1)
name_entry.pack(anchor=CENTER, expand=1)
check_name.pack(anchor=CENTER, expand=1)
label.pack(anchor=CENTER, expand=1)
url_entry.pack(anchor=CENTER, expand=1)
file_format.pack(anchor=CENTER, expand=1)
format_entry.pack(anchor=CENTER, expand=1)
format_entry.insert(0, '.')
check_format.pack(anchor=CENTER)
output_path.pack(anchor=CENTER, expand=1)
output_entry.pack(anchor=CENTER, expand=1)
check_default.pack(anchor=CENTER, expand=1)
inter_frame.pack(expand=1)
root.mainloop()
# the end!
main_menu()
根据您的代码，您只需更改 download_image() 函数中的以下行：
urllib.request.urlretrieve(url, path.replace("\", "\\") + fullname)
至：
threading.Thread(target=urllib.request.urlretrieve,
args=(url, path.replace("\", "\\")+fullname), daemon=True).start()
当然需要import threading.
更新： 在线程中创建 download_image() 运行，添加一个函数：
def start_download():
threading.Thread(target=download_image, daemon=True).start()
并将 download_button 的 command 选项设置为这个新函数：
download_button = Button(body_frame, text="Download!",
command=start_download, border=3, width=20, height=5)
我是 python 的新手，我正在 python 使用 tkinter 和 urllib 创建这个应用程序。基本上，程序获取文件的 URL、名称、格式和路径，然后在用户点击“下载”按钮时下载文件。问题是没有线程程序会冻结，直到下载完成，我不希望这种情况发生。所以经过一些研究，我发现线程可以帮助解决这个问题。使用线程后，我发现我只能启动一个线程一次，这意味着用户只能下载一个 file.So 我发现为了让用户一次下载多个文件，只要用户点击下载按钮程序应该为该下载创建一个新线程，这甚至使用户能够一次下载多个文件。问题是我不知道如何编写这个算法。如果有人帮助我，我将非常感激。 我的代码没有线程：
from tkinter import *
from tkinter import font as tkFont
import random
import urllib.request
import requests
import wget
def printsth():
print("Yay it works! ")
def main_menu():
root = Tk()
root.title('8-bit downloader ')
root.iconbitmap(r"C:\Users\rayanravesh\PycharmProjects\GUI_Calculator\icon.ico")
root.geometry("600x300")
# the top menu
num = IntVar()
chum = IntVar()
var = IntVar()
menu = Menu(root)
root.config(menu=menu)
submenu = Menu(menu)
menu.add_cascade(label="Settings", menu=submenu)
def custom_op():
custom = Toplevel()
custom.iconbitmap(r"C:\Users\rayanravesh\PycharmProjects\GUI_Calculator\icon.ico")
submenu.add_command(label="Customization ", command=custom_op)
def settings_op():
global gps
set_win = Toplevel()
set_win.iconbitmap(r"C:\Users\rayanravesh\PycharmProjects\GUI_Calculator\icon.ico")
path_label = Label(set_win, text="Current default download path: ")
path_entry = Entry(set_win, width=30)
file_read = open('Data.txt', 'r')
data_base = file_read.read()
path_entry.insert(0, data_base)
file_read.close()
def default_output():
global location
file_read2 = open('Data.txt', 'r+')
file_read2.truncate(0)
file_read2.close()
write_file2 = open('Data.txt', 'w')
write_file2.write(path_entry.get())
write_file2.close()
location = path_entry.get() + "\"
default_location = location.replace("\", "\\")
path_btn = Button(set_win, text="Submit ", command=default_output)
path_label.pack(anchor=CENTER, expand=1)
path_entry.pack(anchor=CENTER, expand=1)
path_btn.pack(anchor=CENTER, expand=1)
submenu.add_command(label="Settings ", command=settings_op)
submenu.add_separator()
submenu.add_command(label="Exit", command=root.destroy)
# the section menu
editmenu = Menu(menu)
menu.add_cascade(label="Sections(soon)", menu=editmenu)
editmenu.add_command(label="Downloader", command=printsth)
editmenu.add_command(label="Converter", command=printsth)
editmenu.add_command(label="Media Player", command=printsth)
editmenu.add_command(label="Editor", command=printsth)
# the tool bar
toolbar = Frame(root, bg="light gray")
insert_button = Button(toolbar, text="Insert an image", command=printsth)
insert_button.pack(side=LEFT, padx=2, pady=2)
print_button = Button(toolbar, text="Print", command=printsth)
print_button.pack(side=LEFT, padx=2, pady=2)
toolbar.pack(side=TOP, fill=X)
# the download function
def download_image():
global formatname
if num.get() == 1:
name = random.randrange(1, 1000000)
else:
name = str(name_entry.get())
formatname = str(format_entry.get())
if var.get() == 1:
operator = str(url_entry.get())
formatname = '.' + operator[-3] + operator[-2] + operator[-1]
else:
pass
fullname = str(name) + formatname
url = str(url_entry.get())
fw = open('file-size.txt', 'w')
file_size = int(requests.head(url, headers={'accept-encoding': ''}).headers['Content-Length'])
fw.write(str(file_size))
fw.close()
path = str(output_entry.get()) + "\"
if chum.get() == 1:
filee = open('Data.txt', 'r')
destination = filee.read()
path = destination + "\"
output_entry.insert(0, destination)
filee.close()
else:
output_entry.delete(0, END)
urllib.request.urlretrieve(url, path.replace("\", "\\") + fullname)
# the status bar
status_bar = Label(root, text="Downloading...", bd=1, relief=SUNKEN, anchor=W)
status_bar.pack(side=BOTTOM, fill=X)
# the download frame
body_frame = Frame(root, bg="light blue")
download_button = Button(body_frame, text="Download! ", command=download_image, border=3, width=20, height=5)
download_design = tkFont.Font(size=12, slant='italic')
download_button['font'] = download_design
download_button.pack(side=LEFT, pady=5, padx=5)
body_frame.pack(side=LEFT, fill=Y)
# the main interaction menu
inter_frame = Frame(root)
url_entry = Entry(inter_frame, width=30)
label = Label(inter_frame, text="Enter the image URL: ")
file_format = Label(inter_frame, text="Choose your file format: ")
format_entry = Entry(inter_frame, width=30)
file_name = Label(inter_frame, text="File's name: ")
name_entry = Entry(inter_frame, width=30)
check_name = Checkbutton(inter_frame, text="Give a random name", variable=num)
check_format = Checkbutton(inter_frame, text="Download with default format", variable=var)
check_default = Checkbutton(inter_frame, text="Download to default path", variable=chum)
check_default.deselect()
output_path = Label(inter_frame, text="Choose output path: ")
output_entry = Entry(inter_frame, width=30)
file_name.pack(anchor=CENTER, expand=1)
name_entry.pack(anchor=CENTER, expand=1)
check_name.pack(anchor=CENTER, expand=1)
label.pack(anchor=CENTER, expand=1)
url_entry.pack(anchor=CENTER, expand=1)
file_format.pack(anchor=CENTER, expand=1)
format_entry.pack(anchor=CENTER, expand=1)
format_entry.insert(0, '.')
check_format.pack(anchor=CENTER)
output_path.pack(anchor=CENTER, expand=1)
output_entry.pack(anchor=CENTER, expand=1)
check_default.pack(anchor=CENTER, expand=1)
inter_frame.pack(expand=1)
root.mainloop()
# the end!
main_menu()
根据您的代码，您只需更改 download_image() 函数中的以下行：
urllib.request.urlretrieve(url, path.replace("\", "\\") + fullname)
至：
threading.Thread(target=urllib.request.urlretrieve,
args=(url, path.replace("\", "\\")+fullname), daemon=True).start()
当然需要import threading.
更新： 在线程中创建 download_image() 运行，添加一个函数：
def start_download():
threading.Thread(target=download_image, daemon=True).start()
并将 download_button 的 command 选项设置为这个新函数：
download_button = Button(body_frame, text="Download!",
command=start_download, border=3, width=20, height=5)