我正在python中编写一个程序，它将处理从某个excel文件中读取的大量数据。我使用Tkinter为这个程序构建了一个GUI。我知道Tkinter是单线程的，因此打开文件并进行一些处理我使用的线程不会阻止GUI。其中一个线程任务是填充一个列表（在我的代码中称为columnList）并在optionmenu中使用其元素作为选项，因此在线程完成之前，选项菜单为空，因此我使用join（）来让main线程等待工作线程。而且，问题来了，只要工作线程正在执行GUI就没有响应（大约7秒），但之后它将正常工作。
我想使用一些图形指示符来指示正在加载某些内容，同时阻止GUI窗口，以便用户无法单击它。线程停止后，指示符应该消失，并且应该再次启用GUI。我搜索了这样一个概念，但我没有在网上找到这样的东西，这个问题在这里，Python Tkinter: loading screen与我的情况非常相似，但它没有答案。
这是我的代码的一部分，我需要应用这个概念：
__author__ = 'Dania'
import threading
from Tkinter import *
from tkFileDialog import askopenfilename
import numpy as np
import xlrd
global x
global v
x = np.ones(5)
v= np.ones(5)
global columnList
columnList=""
def open_file (file_name):
try:
workbook = xlrd.open_workbook(file_name)
sheet=workbook.sheet_by_index(0)
global columns
columns = [] #this is a list, in each index we will store a numpy array of a column values.
for i in range (0,sheet.ncols-1):
columns.append(np.array (sheet.col_values(i,1))) # make a list, each index has a numpy array that represnts a column. 1 means start from row 1 (leave the label)
if (i!=0):
columns[i]= columns[i].astype(np.float)
#Preprocessing columns[0]:
m= columns [0]
for i in range (m.shape[0]):
m[i]= m[i]*2 +1
m=m.astype(np.int)
columns[0]=m
global columnList
columnList= np.array(sheet.row_values(0)) #I was using sheet.row(0), but this is better since it doesn't return a 'u'
columnList=columnList.astype(np.str)
# removing nans:
index=input("enter the column index to interpolate: ") #this should be user input
n= columns [index]
for i in range (n.shape[0]-1, -1, -1):
if (np.isnan(n[i])):
n=np.delete(n,i)
columns[0]=np.delete(columns[0],i)
columns [index]= np.delete(columns[index],i)
except IOError:
print ("The specified file was not found")
global x
np.resize(x, m.shape[0])
x=columns[0]
global v
np.resize(v,n.shape[0])
v=columns[index]
#return columns [0], columns [index]
class Interface:
def __init__(self, master):
self.title= Label(master,text="Kriging Missing data Imputation", fg="blue", font=("Helvetica", 18))
self.select_file= Label (master, text="Select the file that contains the data (must be an excel file): ", font=("Helvetica", 12))
self.title.grid (row=1, column=5, columnspan= 4, pady= (20,0))
self.select_file.grid (row=3, column=1, sticky=W, pady=(20,0), padx=(5,2))
self.browse_button= Button (master, text="Browse", command=self.browser, font=("Helvetica", 12), width=12)
self.browse_button.grid (row=3, column=3, pady=(20,0))
self.varLoc= StringVar(master)
self.varLoc.set("status")
self.varColumn= StringVar(master)
self.varColumn.set("")
self.locationColumn= Label(master,text="Select a column as a location indicator", font=("Helvetica", 12))
self.columnLabel= Label(master,text="Select a column to process", font=("Helvetica", 12))
global locationOption
global columnOption
columnOption= OptionMenu (master, self.varColumn,"",*columnList)
locationOption= OptionMenu (master, self.varLoc,"",*columnList)
self.locationColumn.grid (row=5, column=1, pady=(20,0), sticky=W, padx=(5,0))
locationOption.grid (row=5, column=3, pady=(20,0))
self.columnLabel.grid (row=7, column=1, pady=(20,0), sticky=W, padx=(5,0))
columnOption.grid(row=7, column= 3, pady= (20,0))
self.missing_label= Label(master, text="Select missing data indicator: ", font=("Helvetica", 12))
self.var = StringVar (master)
self.var.set("nan")
self.menu= OptionMenu (master, self.var,"nan", "?", "*")
self.missing_label.grid (row=9, column=1, padx=(5,2), pady= (20,0), sticky=W)
self.menu.grid(row=9, column=3, pady= (20,0))
self.extrapolate= Label (master, text="Select a range for extrapolation (max=800): ", font=("Helvetica", 12))
self.max_extra= Entry (master)
self.extrapolate.grid (row=11, column=1, padx=(5,2), pady= (20,0), sticky=W)
self.max_extra.grid (row=11, column=3, pady=(20,0))
self.a_label= Label (master, text="enter the value of a (range): ", font=("Helvetica", 12))
self.a_value= Entry (master)
self.a_label.grid (row=13, column=1, padx=(5,2), pady=(20,0), sticky=W)
self.a_value.grid (row=13, column=3, pady=(20,0))
self.start_button= Button (master, text="Start", font=("Helvetica", 12), width=12)
self.pause_button= Button (master, text= "Pause", font=("Helvetica", 12),width=12)
self.stop_button= Button (master, text="stop", font=("Helvetica", 12),width=12)
self.start_button.grid (row=15, column=1, pady=(30,0) )
self.pause_button.grid (row=15, column=2, pady=(30,0))
self.stop_button.grid (row=15, column=3, pady=(30,0))
def browser (self):
filename = askopenfilename()
#indicator should start here.
t=threading.Thread (target=open_file, args=(filename, ))
t.start()
t.join() #I use join because if I didn't,next lines will execute before open_file is completed, this will make columnList empty and the code will not execute.
#indicator should end here.
opt=columnOption.children ['menu']
optLoc= locationOption.children ['menu']
optLoc.entryconfig (0,label= columnList [0], command=self.justamethod)
opt.entryconfig (0, label= columnList [0], command=self.justamethod)
for i in range(1,len (columnList)):
opt.add_command (label=columnList[i], command=self.justamethod)
optLoc.add_command (label=columnList[i], command=self.justamethod)
def justamethod (self):
print("method is called")
print(self.varLoc.get())
window= Tk () #main window.
starter= Interface (window)
window.mainloop() #keep the window open until the user decides to close it.
我试图在方法浏览器中添加一些进度条，如下所示，
def browser (self):
filename = askopenfilename()
progressbar = ttk.Progressbar(orient=HORIZONTAL, length=200, mode='determinate')
progressbar.pack(side="bottom")
progressbar.start()
t=threading.Thread (target=open_file, args=(filename, ))
t.start()
t.join() #I use join because if I didn't,next lines will execute before open_file is completed, this will make columnList empty and the code will not execute.
progressbar.stop()
opt=columnOption.children ['menu']
opt.entryconfig (0, label= columnList [0], command=self.justamethod)
for i in range(1,len (columnList)):
opt.add_command (label=columnList[i], command=self.justamethod)
optLoc.add_command (label=columnList[i], command=self.justamethod)
def justamethod (self):
print("method is called")
window= Tk () #main window.
starter= Interface (window)
window.mainloop() #keep the window open until the user decides to close it.
但是，上面的代码甚至没有显示进度条，这不是我真正需要的。
编辑：编辑代码并修复空格。一个有效的代码示例是第一个代码段中的代码示例。
任何人都可以告诉我该怎么做？
感谢任何帮助。
感谢。
答案 0 :(得分：1)
使用后台线程读取文件的一个优点是当前线程不会阻塞并可以继续运行。通过在t.join()之后直接调用t.start，如果您刚刚在当前线程中执行了读操作，则阻止GUI没有区别。
相反，在执行操作之前，如何将光标更改为wait光标？我已经简化了你的代码，但是这样：
from tkinter import *
import time
class Interface:
def __init__(self, master):
self.master = master
self.browse_button= Button (master, text="Browse", command=self.browser)
self.browse_button.pack()
def browser (self):
self.master.config(cursor="wait")
self.master.update()
self.read_file("filename")
self.master.config(cursor="")
def read_file (self, filename):
time.sleep(5) # actually do the read file operation here
window = Tk()
starter = Interface(window)
window.mainloop()
Thread和Progressbar。
from tkinter import *
from tkinter.ttk import *
import time
import threading
class Interface:
def __init__(self, master):
self.master = master
self.browse_button= Button (master, text="Browse", command=self.browser)
self.browse_button.pack()
self.progressbar = Progressbar(mode="determinate", maximum=75)
def browser (self):
t = threading.Thread(target=self.read_file, args=("filename",))
self.progressbar.pack()
self.browse_button.config(state="disabled")
self.master.config(cursor="wait")
self.master.update()
t.start()
while t.is_alive():
self.progressbar.step(1)
self.master.update_idletasks() # or try self.master.update()
t.join(0.1)
self.progressbar.config(value="0")
self.progressbar.pack_forget()
self.browse_button.config(state="enabled")
self.master.config(cursor="")
def read_file (self, filename):
time.sleep(7) # actually do the read here
window = Tk()
starter = Interface(window)
window.mainloop()
注意：我没有做太多的GUI编码，这可能不是通过并试图提供帮助的最佳解决方案！ ：）
编辑2：考虑一下。由于您不确定读取将花费多长时间，因此您可以使用此方法在进度条的两端之间来回反弹指示器。
from tkinter import *
from tkinter.ttk import *
import time
import threading
class Interface:
def __init__(self, master):
self.master = master
self.browse_button= Button (master, text="Browse", command=self.browser)
self.browse_button.pack()
# Create an indeterminate progressbar here but don't pack it.
# Change the maximum to change speed. Smaller == faster.
self.progressbar = Progressbar(mode="indeterminate", maximum=20)
def browser (self):
# set up thread to do work in
self.thread = threading.Thread(target=self.read_file, args=("filename",))
# disable the button
self.browse_button.config(state="disabled")
# show the progress bar
self.progressbar.pack()
# change the cursor
self.master.config(cursor="wait")
# force Tk to update
self.master.update()
# start the thread and progress bar
self.thread.start()
self.progressbar.start()
# check in 50 milliseconds if the thread has finished
self.master.after(50, self.check_completed)
def check_completed(self):
if self.thread.is_alive():
# if the thread is still alive check again in 50 milliseconds
self.master.after(50, self.check_completed)
else:
# if thread has finished stop and reset everything
self.progressbar.stop()
self.progressbar.pack_forget()
self.browse_button.config(state="enabled")
self.master.config(cursor="")
self.master.update()
# Call method to do rest of work, like displaying the info.
self.display_file()
def read_file (self, filename):
time.sleep(7) # actually do the read here
def display_file(self):
pass # actually display the info here
window = Tk()
starter = Interface(window)
window.mainloop()