添加和删除tkinter帧 - 跟踪实例

Question

我想在Tkinter GUI中创建一堆子帧，每个子帧都包含一些用户输入变量，我需要稍后才能通过唯一每个子帧的ID。我需要能够添加和删除随意子帧，并让他们在一个合理的顺序ID'd（整数从1计数，此刻）

三个问题真的：

1）具体来说，为什么标签小部件显示每个框架的标题不显示？ （这可能是愚蠢的......）

2）具体来说，为什么有时需要两次按下添加或删除按钮来添加或删除一个框架？

3）通常：有更好的方法来解决这个问题吗？在追踪帧实例的意义上。他们现在在列表中...我早些时候开始使用字典，但与...合作更难...有更好的建议吗？

from tkinter import * 
from tkinter.ttk import * 

class AllInstances(Tk): 
    def __init__(self): 
     Tk.__init__(self) 
     self.master_frame = Frame(self) 
     self.master_frame.grid() 
     self.all_instances = [] 

root = AllInstances() 

class OneInstance(): 
    def __init__(self): 
     self.number = len(root.all_instances) + 1 

     var1 = StringVar() 
     var2 = StringVar() 
     var3 = StringVar() 

     self.sub_frame = Frame(root.master_frame) 
     self.sub_frame.grid(column = self.number, row = 0) 

     titletext = StringVar() 
     titletext.set('%s %s' % ('Frame', self.number)) 
     print(titletext.get()) 
     title = Label(self.sub_frame, textvariable = titletext) 
     title.grid() #work out why this label does not display! 

     uservar1 = Entry(self.sub_frame, textvariable = var1) 
     uservar1.grid() 
     uservar2 = Entry(self.sub_frame, textvariable = var2) 
     uservar2.grid() 
     uservar3 = Entry(self.sub_frame, textvariable = var3) 
     uservar3.grid() 
     #etc etc 

     add_button = Button(self.sub_frame, text = 'Add', command = lambda: Create()) 
     add_button.grid() 

     def RemoveInstance(self): 
      if len(root.all_instances) > 1: 
       root.all_instances.remove(self) 
       self.sub_frame.destroy() 

       for instance in root.all_instances: 
        instance.number = (root.all_instances.index(instance) + 1) 
      else: 
       pass 

     remove_button = Button(self.sub_frame, text = 'Remove', command = lambda: RemoveInstance(self)) 
     remove_button.grid() 

     root.all_instances.append(self) 

def Create(): 
    OneInstance() 

Create() 
root.mainloop() 

谢谢... :)

Answer 1

这里是我会做：

1. 建立从FrameAllInstances继承（和重命名为类似 “FrameGroup”）。然后它变成一个“巨型小工具”，子框架可以直接控制。
2. 使您的子帧成为Frame的子类（并将其称为“子帧”）。这也是“megawidget”，它需要被松耦合到其父（即：它不应该知道root.all_instances
3. 有你的添加和删除按钮调用FrameGroup对象的方法

。我还建议不做一个全球进口既然您同时使用TTK和Tkinter的，一会覆盖其他根据其命令对您订购的import语句

下面是与修改的工作，例如：。

import tkinter as tk 

class FrameGroup(tk.Frame): 
    def __init__(self, parent): 
     tk.Frame.__init__(self, parent) 
     self.all_instances = [] 
     self.counter = 0 

    def Add(self): 
     self.counter += 1 
     name = "Frame %s" % self.counter 
     subframe = Subframe(self, name=name) 
     subframe.pack(side="left", fill="y") 
     self.all_instances.append(subframe) 

    def Remove(self, instance): 
     # don't allow the user to destroy the last item 
     if len(self.all_instances) > 1: 
      index = self.all_instances.index(instance) 
      subframe = self.all_instances.pop(index) 
      subframe.destroy() 

    def HowMany(self): 
     return len(self.all_instances) 

    def ShowMe(self): 
     for instance in self.all_instances: 
      print(instance.get()) 

class Subframe(tk.Frame): 
    def __init__(self, parent, name): 
     tk.Frame.__init__(self, parent) 
     self.parent = parent 
     self.e1 = tk.Entry(self) 
     self.e2 = tk.Entry(self) 
     self.e3 = tk.Entry(self) 
     label = tk.Label(self, text=name, anchor="center") 
     add_button = tk.Button(self, text="Add", command=self.parent.Add) 
     remove_button = tk.Button(self, text="Remove", command=lambda: self.parent.Remove(self)) 

     label.pack(side="top", fill="x") 
     self.e1.pack(side="top", fill="x") 
     self.e2.pack(side="top", fill="x") 
     self.e3.pack(side="top", fill="x") 
     add_button.pack(side="top") 
     remove_button.pack(side="top") 

    def get(self): 
     return (self.e1.get(), self.e2.get(), self.e3.get()) 

class GUI(tk.Tk): 
    def __init__(self): 
     tk.Tk.__init__(self) 
     self.master_frame = tk.Frame(self) 
     self.master_frame.grid() 
     self.all_instances = FrameGroup(self.master_frame) 
     self.all_instances.grid() 

     # create the first frame 
     self.all_instances.Add() 

root = GUI() 
root.mainloop()