Tkinter：打开另一个窗口的按钮（并关闭当前窗口）

Question

我正在创建一个“定义测试”类型的程序（用户为每个单词输入单词，词性和同义词，然后程序测验用户在所述信息上）。 在最后的窗口（quizzing窗口），我有一个窗口的布局是这样的：

1/25 What is the definition of _word_? # number out of total + prompt 
Definition: _entry_ # entry fields for information 
Part of Speech: _entry_ 
Next Help Quit # buttons; 'Next' checks the info and goes to the next word 
# 'Help' shows the info and goes to the next word 
# 'Quit' force-quits the program 
Tries Left: 5 # how many tries before the info is shown 

我的问题是“帮助”按钮。通常，只需输入5次错误信息，它将成功创建“帮助”窗口;然而，它仍然保留原来的词（无法回答的那个词），开放。当这个新窗口关闭时，新的单词将显示出来，但会有两个窗口：新单词+旧单词。此外，“帮助”按钮本身引发错误：

>>> 

Traceback (most recent call last): 
    File _filepath_, line 455, in <module> 
    main() 
    File _filepath_, line 68, in main 
    test(screenDim, test_dict) 
    File _filepath_, line 451, in test 
    root.destroy() 
    File "C:\Python2.7.3\lib\lib-tk\Tkinter.py", line 1728, in destroy 
    self.tk.call('destroy', self._w) 
TclError: can't invoke "destroy" command: application has been destroyed 

这里是我的test功能（我修剪了一下代码，因此它更容易发现问题）：

def test(screenDim, test_dict): 
    class TestWords: 
     def __init__(self, master): 
      w, h = screenDim[0], screenDim[1] 
      rootW, rootH, xPos, yPos = int(float(w)/3), int(float(h)/4), w/2 - (w/6), h/2 - (h/8) 
      self.frame = Frame(master) 
      self.frameB = Frame(self.frame) 
      self.frameE = Frame(self.frame) 
      self.posE = Entry(self.frameE, width = 50, justify = CENTER) 
      self.defE = Entry(self.frameE, width = 50, justify = CENTER) 
      self.posE.grid(row = 1, column = 2, pady = 5) 
      self.defE.grid(row = 2, column = 2, pady = 5) 
      # there are a few other widgets/frames that don't pertain to this problem 
      self.goButton = Button(self.frameB, text = 'Next', command = self.getInfo, width = 10) 
      self.helpButton = Button(self.frameB, text = 'Help', command = self.getHelp, width = 10) 
      self.quitButton = Button(self.frameB, text = 'Quit', command = self.quitBox, width = 10, fg = 'red') 
      self.goButton.grid(row = 1, column = 1, padx = 10) 
      self.helpButton.grid(row = 1, column = 2, padx = 10) 
      self.quitButton.grid(row = 1, column = 3, padx = 10) 
      master.geometry("%sx%s+%s+%s" % (rootW, rootH, xPos, yPos)) 
      self.frameE.grid(row = 3, pady = 5) 
      self.frameB.grid(row = 4, padx = rootW/4 - 60, pady = 5) 
      self.frame.grid() 
     def quitBox(self): 
      import sys 
      sys.exit('Program Terminated.') 
     def getHelp(self): 
      triesLeft = 0 
      self.frame.quit() 
      root.destroy() 
     def getInfo(self): 
      info = (self.posE.get(), self.defE.get()) 
      self.frame.quit() 
      return info 
    class GetHelp: 
     def __init__(self, master): 
      w, h = screenDim[0], screenDim[1] 
      rootW, rootH, xPos, yPos = int(float(w)/4), int(float(h)/4), w/2 - (w/8), h/2 - (h/8) 
      self.frame = Frame(master) 
      self.frameB = Frame(self.frame) 
      self.goButton = Button(self.frameB, text = 'Next', command = self.frame.quit, width = 10) 
      self.quitButton = Button(self.frameB, text = 'Quit', command = self.quitBox, fg = 'red', width = 10) 
      self.goButton.grid(row = 1, column = 1, padx = 5) 
      self.quitButton.grid(row = 1, column = 2, padx = 5) 
      self.frameB.grid(row = 2, padx = rootW/4 - 20, pady = 5) 
      master.geometry("%sx%s+%s+%s" % (rootW, rootH, xPos, yPos)) 
      self.frame.grid() 
      # again, a few widgets were removed for brevity 
     def quitBox(self): 
      import sys 
      sys.exit('Program Terminated.') 
    n, words, reviewWords = len(test_dict.keys()), test_dict.keys(), [] 
    shuffle(words) 
    for i in range(n): 
     word, triesLeft = words[i], 4 
     while triesLeft >= 0: 
      root = Tk(className = ' Definition Tester') 
      root.columnconfigure(0, weight=1) 
      root.rowconfigure(0, weight=1) 
      app = TestWords(root) 
      root.mainloop() 
      try: 
       info = app.getInfo() 
      except TclError: 
       info = ('', '') 
      if info[0] == test_dict[word][0] and info[1] in test_dict[word][1]: 
       del words[i] 
       root.destroy() 
       break 
      elif triesLeft == 0: 
       reviewWords.append(word) 
       root = Tk(className = ' Definition Tester') 
       root.columnconfigure(0, weight=1) 
       root.rowconfigure(0, weight=1) 
       app = GetHelp(root) 
       root.mainloop() 
       break 
      else: 
       triesLeft -= 1 
       root.destroy() 

的在剩下0次尝试后，程序会自动显示帮助窗口。因此，“帮助”按钮将triesLeft设置为0.但是，这似乎并未打开窗口。谢谢！

Answer 1

您需要重新构建您的解决方案，以便您只创建一个根窗口，并且只运行单个实例mainloop。不要一遍又一遍地创建和销毁根窗口，而是创建并销毁Toplevel的实例。 Tkinter根本不是为了创建和销毁多个根窗口而设计的。