2017-08-12 45 views
0

我一直在制作一个简单的程序来进行文件夹备份。控制台版本完美无瑕,但在处理Tkinter版本时遇到了一个问题。我想以类似网格的方式显示按钮,每个按钮将负责给定文件夹的备份,并且我希望每个“页面”限制20个按钮。我设法创建简单的分页,仅在增加页码时才起作用。当我尝试做减少页码,控制台会提示我一个错误:Tkinter元素和分页

Exception in Tkinter callback 
Traceback (most recent call last): 
    File "D:\Programy\Python34\lib\tkinter\__init__.py", line 1533, in __call__ 
    return self.func(*args) 
    File "D:\Rzeczy Mariusza\Python\Backup_manager\main_gui.py", line 83, in 
    go_back_event_handler self.show_avaliable_directories() 
    File "D:\Rzeczy Mariusza\Python\Backup_manager\main_gui.py", line 72, in 
    show_avaliable_directories 
    self.active_directories[i].place(x=_x, y=_y) 
    File "D:\Programy\Python34\lib\tkinter\__init__.py", line 2019, in 
    place_configure + self._options(cnf, kw)) 
_tkinter.TclError: bad window path name ".37362480.37388656" 

类代码:

from tkinter import Label, StringVar 
from tkinter import ttk 


class MainGui(): 

    def __init__(self, main_frame, avaliable_directories): 
     """ 
     Building main elements located in the main_frame. 

     Args: 
      main_frame: instance - module Tkinter class ttk.Frame. 
      avaliable_directories: dict - contains avaliable directories for back up. 
     """ 

     self.main_frame = main_frame 
     self.avaliable_directories = avaliable_directories 

     self.choose_backup_dir_name = StringVar() 
     self.style_1 = ttk.Style() 
     self.style_1.map('directory.TButton', 
      foreground=[('!disabled', '#%02x%02x%02x' %(0, 0, 0)), ('disabled', '#%02x%02x%02x' %(115, 115, 115))], 
      background=[('!disabled', '#%02x%02x%02x' %(40, 240, 240)), ('disabled', '#%02x%02x%02x' %(240, 240, 240))]) 

     self.pagination = 1 
     self.button_directories = [] 
     self.active_directories = [] 

     for element in self.avaliable_directories: 
      temp = ttk.Button(
       self.main_frame, 
       width=20, 
       style='directory.TButton', 
       text=element 
       ) 
      self.button_directories.append(temp) 

     if len(self.button_directories) > 20: 
      self.go_back = ttk.Button(self.main_frame, width=2, text='<') 
      self.go_back.place(x=325, y=540) 
      self.go_back.bind('<Button-1>', self.go_back_event_handler) 

      self.go_forward = ttk.Button(self.main_frame, width=2, text='>') 
      self.go_forward.place(x=350, y=540) 
      self.go_forward.bind('<Button-1>', self.go_forward_event_handler) 

     self.show_avaliable_directories() 

    # Interesting part starts here. 
    def show_avaliable_directories(self): 
     for i, element in enumerate(self.button_directories[20*(self.pagination-1):20*self.pagination]):# Implementation of pagination. 
      _x = 20+200*(i//10) 
      _y = 20+40*(i%10) 
      element.place(x=_x, y=_y) 
      # Placed elements are assigned to new list. 
      # When discarded (bellow) all elements from the list are destroyed. 
      self.active_directories.append(element) 

    def clear_active_directories(self): 
     for element in self.active_directories: 
      element.destroy() 
     self.active_directories = [] 

    def go_back_event_handler(self, event): 
     if self.pagination > 1: 
      self.pagination -= 1 
      self.clear_active_directories() 
      self.show_avaliable_directories() 

    def go_forward_event_handler(self, event): 
     limit = (len(self.button_directories)//20)+1 
     if self.pagination < limit: 
      self.pagination += 1 
      self.clear_active_directories() 
      self.show_avaliable_directories() 

我不知道为什么,当我增加了页码它的工作原理,但它当我尝试减少页码时不会。谢谢你的帮助。

回答

0

我发现原始答案。每次程序显示新的按钮时,都会创建所有元素(按钮)的列表。当页面被改变时,程序将销毁列表中的所有元素,甚至是未使用的元素。这可能无效但有效。

from tkinter import Label, StringVar 
from tkinter import ttk 


class MainGui(): 

    def __init__(self, main_frame, avaliable_directories): 
     """ 
     Building main elements located in the main_frame. 

     Args: 
      main_frame: instance - module Tkinter class ttk.Frame. 
      avaliable_directories: dict - contains avaliable directories for back up. 
     """ 

     self.main_frame = main_frame 
     self.avaliable_directories = avaliable_directories 

     self.choose_backup_dir_name = StringVar() 
     self.style_1 = ttk.Style() 
     self.style_1.map('directory.TButton', 
      foreground=[('!disabled', '#%02x%02x%02x' %(0, 0, 0)), ('disabled', '#%02x%02x%02x' %(115, 115, 115))], 
      background=[('!disabled', '#%02x%02x%02x' %(40, 240, 240)), ('disabled', '#%02x%02x%02x' %(240, 240, 240))]) 

     self.pagination = 1 
     self.button_directories = [] 

     if len(self.avaliable_directories) > 20: 
      self.go_back = ttk.Button(self.main_frame, width=2, text='<') 
      self.go_back.place(x=325, y=540) 
      self.go_back.bind('<Button-1>', self.go_back_event_handler) 

      self.go_forward = ttk.Button(self.main_frame, width=2, text='>') 
      self.go_forward.place(x=350, y=540) 
      self.go_forward.bind('<Button-1>', self.go_forward_event_handler) 

     self.show_avaliable_directories() 

    def show_avaliable_directories(self): 
     for element in self.avaliable_directories: 
      temp = ttk.Button(
       self.main_frame, 
       width=20, 
       style='directory.TButton', 
       text=element 
       ) 
      self.button_directories.append(temp) 

     for i, element in enumerate(self.button_directories[20*(self.pagination-1):20*self.pagination]): 
      _x = 20+200*(i//10) 
      _y = 20+40*(i%10) 
      element.place(x=_x, y=_y) 

    def clear_active_directories(self): 
     for element in self.button_directories: 
      element.destroy() 
     self.button_directories = [] 

    def go_back_event_handler(self, event): 
     if self.pagination > 1: 
      self.pagination -= 1 
      self.clear_active_directories() 
      self.show_avaliable_directories() 

    def go_forward_event_handler(self, event): 
     limit = (len(self.button_directories)//20)+1 
     if self.pagination < limit: 
      self.pagination += 1 
      self.clear_active_directories() 
      self.show_avaliable_directories()