Question

我正在尝试使用Tkinter创建一个小程序，它将打开您的数据文件，对数据执行某些操作，并将其保存为新文件。

我想将输入文件的选择与其处理分开，因此我使用了两个不同的帧。但是，我在正确初始化ProcessPage框架时遇到了一些问题，因为在用户指定实际文件名之前，它总是以我的（未定义的）文件名读取，尝试加载数据。

最有可能的是，我错误地测试了全局变量，或者缺少与ProcessPage的init__相比至关重要的东西。

如何在用户声明正确文件之前确保ProcessPage框架在init__期间不尝试读入数据？

我对Tkinter相当缺乏经验，所以我可能会遗漏一些明显的东西。

谢谢！

编辑（10/01/2017）：在ProcessPage类中添加了一个额外的方法（load_file）;从get_filename调用此方法;并声明时间和数据作为全局参数。但是，我不确定后者是否是良好做法。

import Tkinter as tk
from tkFileDialog import askopenfilename
import numpy as np

global time, data
time, data = np.array([]), np.array([])

class MainApp(tk.Tk):    
  def __init__(self, *args, **kwargs):
    tk.Tk.__init__(self, *args, **kwargs)
    container = tk.Frame(self)
    container.pack(side='top', fill='both', expand = True)    
    container.grid_rowconfigure(0, weight=1)
    container.grid_columnconfigure(0, weight=1)

    self.frames = {}
    for F in (LoadPage, ProcessPage):
      frame = F(container, self)
      self.frames[F] = frame
      frame.grid(row=0, column=0, sticky='nsew')
    self.show_frame(LoadPage)

  def show_frame(self, cont):
    frame = self.frames[cont]
    frame.tkraise()

class LoadPage(tk.Frame):
  def __init__(self, parent, controller):
    tk.Frame.__init__(self, parent)

    button1 = tk.Button(self, text='Browse', command = lambda: self.get_filename(controller))
    button1.pack()

    self.filename = tk.StringVar()
    self.filename.set('No File Selected')

    labelFile = tk.Label(self, textvariable=self.filename)
    labelFile.pack()

    button2 = tk.Button(self, text='Proceed and process my data', command = lambda: controller.show_frame(ProcessPage))
    button2.pack()


  def get_filename(self, controller):
    global time, data
    fname = askopenfilename()
    if fname:
        self.filename.set(fname)
        # Extra line below  (10/01/2017)
        controller.frames[ProcessPage].load_file(fname)

class ProcessPage(tk.Frame):
  def __init__(self, parent, controller):
    tk.Frame.__init__(self, parent)

  # Extra method, as suggested   (10/01/2017)
  def load_file(self, filename):
    global time, data
    time, data = np.loadtxt(filename, usecols=(0,1), unpack=True)



app = MainApp()
app.mainloop()

Answer 1

最终实现，其中调用方法ProcessPage.load_file（）来读取数据。读入数据并将其存储为ProcessPage中的变量（self.time和self.data）。

从LoadPage.start_processing（）读取数据，该页面现在链接到button2，因此数据和读入的浏览是分开的。

import Tkinter as tk
from tkFileDialog import askopenfilename
import numpy as np

class MainApp(tk.Tk):    
  def __init__(self, *args, **kwargs):
    tk.Tk.__init__(self, *args, **kwargs)
    container = tk.Frame(self)
    container.pack(side='top', fill='both', expand = True)    
    container.grid_rowconfigure(0, weight=1)
    container.grid_columnconfigure(0, weight=1)

    self.frames = {}
    for F in (LoadPage, ProcessPage):
      frame = F(container, self)
      self.frames[F] = frame
      frame.grid(row=0, column=0, sticky='nsew')
    self.show_frame(LoadPage)

  def show_frame(self, cont):
    frame = self.frames[cont]
    frame.tkraise()

class LoadPage(tk.Frame):
  def __init__(self, parent, controller):
    tk.Frame.__init__(self, parent)

    button1 = tk.Button(self, text='Browse', command = self.get_filename)
    button1.pack()

    self.filename = tk.StringVar()
    self.filename.set('No File Selected')

    labelFile = tk.Label(self, textvariable=self.filename)
    labelFile.pack()

    button2 = tk.Button(self, text='Proceed and process my data', command = lambda: self.start_processing(controller))
    button2.pack()


  def get_filename(self):
    fname = askopenfilename()
    if fname:
        self.filename.set(fname)
        return

  # Extra method below  (10/01/2017)
  def start_processing(self, controller):
    controller.frames[ProcessPage].load_file(self.filename.get())
    controller.show_frame(ProcessPage)

class ProcessPage(tk.Frame):
  def __init__(self, parent, controller):
    tk.Frame.__init__(self, parent)
    # Initialised the variables (10/01/2017)
    self.time = np.array([])
    self.data = np.array([])

  # Extra method, as suggested   (10/01/2017)
  def load_file(self, filename):
    self.time, self.data = np.loadtxt(filename, usecols=(0,1), unpack=True)   

app = MainApp()
app.mainloop()

Tkinter：在新帧中加载/处理输入文件

1 个答案: