Python 2.7 - 如何在Tkinter GUI中使用Observer，在哪些帧之间切换？
问题描述：
我目前正在基于线程How to get variable data from a class的GUI上工作。由于会有大量的数据需要处理，我想使用一个Model-Class，它通过Observer得到它的更新。Python 2.7 - 如何在Tkinter GUI中使用Observer，在哪些帧之间切换？
眼下，在页面的一个变化在ttk.Combobox通过<<ComboboxSelect>>注册，被拉进Controller的变量self.shared_data并传递给Model。这样，不使用Oberserver/Observable逻辑。相反，只要用户在GUI中采取相应的操作，就会更改Model中的数据。
I，然而，会喜欢不必须使用绑定像<<ComboboxSelect>>以改变Model相应的数据，但是观察员/可观察的逻辑，用于检测，即，即条目"Inputformat"在词典self.shared_data的Controller内是然后刷新Model的数据，即self.model_data，其中保存了ttk.Combobox的实际状态。
总之，我要实现以下，通过使用观测器：
用户在ttk.Combobox选择即“条目01” - > self.shared_data [“Inputformat”]在Controller现在充满用“Entry 01” - > Observer/Observable逻辑检测到 - >Model中的相应变量正在改变。
为了让您有一些工作，这里是代码。
# -*- coding: utf-8 -*-
import csv
import Tkinter as tk # python2
import ttk
import tkFileDialog
# Register a new csv dialect for global use.
# Its delimiter shall be the semicolon:
csv.register_dialect('excel-semicolon', delimiter = ';')
font = ('Calibri', 12)
'''
###############################################################################
# Model #
###############################################################################
'''
class Model:
def __init__(self, *args, **kwargs):
# There shall be a variable, which is updated every time the entry
# of the combobox is changed
self.model_keys = {}
self.model_directories = {}
def set_keys(self, keys_model):
self.model_keys = keys_model
keys = []
keyentries = []
for key in self.model_keys:
keys.append(key)
for entry in self.model_keys:
keyentries.append(self.model_keys[entry].get())
print "model_keys: {0}".format(keys)
print "model_keyentries: {0}".format(keyentries)
def get_keys(self):
keys_model = self.model_keys
return(keys_model)
def set_directories(self, model_directories):
self.model_directories = model_directories
print "Directories: {0}".format(self.model_directories)
def get_directories(self):
model_directories = self.model_directories
return(model_directories)
'''
###############################################################################
# Controller #
###############################################################################
'''
# controller handles the following: shown pages (View), calculations
# (to be implemented), datasets (Model), communication
class PageControl(tk.Tk):
''' Initialisations '''
def __init__(self, *args, **kwargs):
tk.Tk.__init__(self, *args, **kwargs) # init
tk.Tk.wm_title(self, "MCR-ALS-Converter") # title
# initiate Model
self.model = Model()
# file dialog options
self.file_opt = self.file_dialog_options()
# stores checkboxstatus, comboboxselections etc.
self.shared_keys = self.keys()
# creates the frames, which are stacked all over each other
container = self.create_frame()
self.stack_frames(container)
#creates the menubar for all frames
self.create_menubar(container)
# raises the chosen frame over the others
self.frame = self.show_frame("StartPage")
''' Methods to show View'''
# frame, which is the container for all pages
def create_frame(self):
# the container is where we'll stack a bunch of frames
# on top of each other, then the one we want visible
# will be raised above the others
container = ttk.Frame(self)
container.pack(side="top", fill="both", expand=True)
container.grid_rowconfigure(0, weight=1)
container.grid_columnconfigure(0, weight=1)
return(container)
def stack_frames(self, container):
self.frames = {}
for F in (StartPage, PageOne, PageTwo):
page_name = F.__name__
frame = F(parent = container, controller = self)
self.frames[page_name] = frame
# put all of the pages in the same location;
# the one on the top of the stacking order
# will be the one that is visible.
frame.grid(row=0, column=0, sticky="nsew")
# overarching menubar, seen by all pages
def create_menubar(self, container):
# the menubar is going to be seen by all pages
menubar = tk.Menu(container)
menubar.add_command(label = "Quit", command = lambda: app.destroy())
tk.Tk.config(self, menu = menubar)
# function of the controller, to show the desired frame
def show_frame(self, page_name):
#Show the frame for the given page name
frame = self.frames[page_name]
frame.tkraise()
return(frame)
''' Push and Pull of Data from and to Model '''
# calls the method, which pushes the keys in Model (setter)
def push_keys(self):
self.model.set_keys(self.shared_keys)
# calls the method, which pulls the key data from Model (getter)
def pull_keys(self):
pulled_keys = self.model.get_keys()
return(pulled_keys)
# calls the method, which pushes the directory data in Model (setter)
def push_directories(self, directories):
self.model.set_directories(directories)
# calls the method, which pulls the directory data from Model (getter)
def pull_directories(self):
directories = self.model.get_directories()
return(directories)
''' Keys '''
# dictionary with all the variables regarding widgetstatus like checkbox checked
def keys(self):
keys = {}
keys["Inputformat"] = tk.StringVar()
keys["Outputformat"] = tk.StringVar()
return(keys)
''' Options '''
# function, which defines the options for file input and output
def file_dialog_options(self):
#Options for saving and loading of files:
options = {}
options['defaultextension'] = '.csv'
options['filetypes'] = [('Comma-Seperated Values', '.csv'),
('ASCII-File','.asc'),
('Normal Text File','.txt')]
options['initialdir'] = 'C//'
options['initialfile'] = ''
options['parent'] = self
options['title'] = 'MCR-ALS Data Preprocessing'
return(options)
''' Methods (bindings) for PageOne '''
def open_button(self):
self.get_directories()
''' Methods (functions) for PageOne '''
# UI, where the user can selected data, that shall be opened
def get_directories(self):
# open files
file_input = tkFileDialog.askopenfilenames(** self.file_opt)
file_input = sorted(list(file_input))
# create dictionary
file_input_dict = {}
file_input_dict["Input_Directories"] = file_input
self.push_directories(file_input_dict)
'''
###############################################################################
# View #
###############################################################################
'''
class StartPage(ttk.Frame):
''' Initialisations '''
def __init__(self, parent, controller):
ttk.Frame.__init__(self, parent)
self.controller = controller
self.labels()
self.buttons()
''' Widgets '''
def labels(self):
label = tk.Label(self, text = "This is the start page", font = font)
label.pack(side = "top", fill = "x", pady = 10)
def buttons(self):
button1 = ttk.Button(self, text = "Go to Page One",
command = lambda: self.controller.show_frame("PageOne"))
button2 = ttk.Button(self, text = "Go to Page Two",
command = lambda: self.controller.show_frame("PageTwo"))
button_close = ttk.Button(self, text = "Close",
command = lambda: app.destroy())
button1.pack(side = "top", fill = "x", pady = 10)
button2.pack(side = "top", fill = "x", pady = 10)
button_close.pack(side = "top", fill = "x", pady = 10)
class PageOne(ttk.Frame):
''' Initialisations '''
def __init__(self, parent, controller):
ttk.Frame.__init__(self, parent)
self.controller = controller
self.labels()
self.buttons()
self.combobox()
''' Widgets '''
def labels(self):
label = tk.Label(self, text = "On this page, you can read data", font = font)
label.pack(side = "top", fill = "x", pady = 10)
def buttons(self):
button_open = ttk.Button(self, text = "Open",
command = lambda: self.controller.open_button())
button_forward = ttk.Button(self, text = "Next Page >>",
command = lambda: self.controller.show_frame("PageTwo"))
button_back = ttk.Button(self, text = "<< Go back",
command = lambda: self.controller.show_frame("StartPage"))
button_home = ttk.Button(self, text = "Home",
command = lambda: self.controller.show_frame("StartPage"))
button_close = ttk.Button(self, text = "Close",
command = lambda: app.destroy())
button_open.pack(side = "top", fill = "x", pady = 10)
button_forward.pack(side = "top", fill = "x", pady = 10)
button_back.pack(side = "top", fill = "x", pady = 10)
button_home.pack(side = "top", fill = "x", pady = 10)
button_close.pack(side = "top", fill = "x", pady = 10)
def combobox(self):
entries = ("", "Inputformat_01", "Inputformat_02", "Inputformat_03")
combobox = ttk.Combobox(self, state = 'readonly', values = entries,
textvariable = self.controller.shared_keys["Inputformat"])
combobox.current(0)
combobox.bind('<<ComboboxSelected>>', self.updater)
combobox.pack(side = "top", fill = "x", pady = 10)
''' Bindings '''
# wrapper, which notifies the controller, that it can update keys in Model
def updater(self, event):
self.controller.push_keys()
class PageTwo(ttk.Frame):
''' Initialisations '''
def __init__(self, parent, controller):
ttk.Frame.__init__(self, parent)
self.controller = controller
self.labels()
self.buttons()
self.combobox()
''' Widgets '''
def labels(self):
label = tk.Label(self, text = "This is page 2", font = font)
label.pack(side = "top", fill = "x", pady = 10)
def buttons(self):
button_back = ttk.Button(self, text = "<< Go back",
command = lambda: self.controller.show_frame("PageOne"))
button_home = ttk.Button(self, text = "Home",
command = lambda: self.controller.show_frame("StartPage"))
button_close = ttk.Button(self, text = "Close",
command = lambda: app.destroy())
button_back.pack(side = "top", fill = "x", pady = 10)
button_home.pack(side = "top", fill = "x", pady = 10)
button_close.pack(side = "top", fill = "x", pady = 10)
def combobox(self):
entries = ("Outputformat_01", "Outputformat_02")
combobox = ttk.Combobox(self, state = 'readonly', values = entries,
textvariable = self.controller.shared_keys["Outputformat"])
combobox.bind('<<ComboboxSelected>>', self.updater)
combobox.pack(side = "top", fill = "x", pady = 10)
''' Bindings '''
# wrapper, which notifies the controller, that it can update keys in Model
def updater(self, event):
self.controller.push_keys()
if __name__ == "__main__":
app = PageControl()
app.mainloop()
答
由于我无法实现Observer来观看像ttk.Combobox这样的小部件，因此我决定创建一个解决方法。下面是我采取的步骤，以便通过Bryan Oakleys示例（链接在问题中）实现MVC体系结构，每当用户在视图（GUI）中执行操作时，都会通过控制器类刷新其模型类。
第1步：添加一个模型类
首先，为了使用MVC架构，我们有单独的代码转换成模型，视图和控制。在这个例子中，型号是class Model:，控制是class PageControl(tk.Tk):，查看的是页面class StartPage(tk.Frame),PageOne(tk.Frame)和PageTwo(tk.Frame)。
第2步：设置你的模型类
现在我们必须对我们要在模型类变量决定。在这个例子中，我们有目录和键（组合框的状态），我们要保存在字典中。将它们设置为空之后，我们所要做的就是为每个变量添加setter和getters，这样我们就可以刷新模型中的数据，并且还可以检索一些数据（如果需要的话）。另外，如果我们想要的话，我们可以为每个变量实施删除方法。
3步：添加推拉的方法来控制类
现在有一个模型类，我们可以通过e refrence它。 G。 self.model = Model() in PageControl(tk.Tk)（对照）。现在我们有基本的工具来通过e在Model中设置数据。 G。 self.model.set_keys(self.shared_keys)，并从Model获得数据。既然我们想要我们的控制类来做到这一点，我们需要一些方法，可以实现这一点。因此，我们将推拉方法添加到PageControl（例如def push_key(self)），后者又可以通过控制器从视图（起始页，PageOne，PageTwo）中引用。
第4步：添加小部件视图类
现在我们必须决定哪些部件应是哪个网页上，你希望他们做什么。在这个例子中，有用于导航的按钮，为了该任务可以忽略它们，两个组合框和一个按钮，用于打开文件对话框。
在这里，我们希望组合框在其更改时刷新其状态，并通过控制器将新状态发送到模型。 PageOne的Open按钮将打开文件对话框，然后用户选择他/她想要打开的文件。我们从这个交互中获得的目录应该通过控制器发送给模型。
第5步：您的所有功能集成到控制器类
既然有控制变量，我们可以用它来refrence方法，即在控制类。这样，我们可以将所有我们的方法从页面外包到控制器中，并通过self.controller.function_of_controller_class引用它们。但我们必须知道，通过lambda:绑定到命令的方法不能返回任何值，但它们在程序启动时也不会被调用。所以记住这一点。
第6步：设置您的绑定和包装
下面我们就来建立.bind()我们的组合框。由于控制器allready已设置为存储数据，并且组合框具有文本变量，因此我们可以通过combobox.bind(<<ComboboxSelect>>)来收集有关组合框状态的信息。我们所要做的就是设置一个被称为的包装，无论何时combobox.bind(<<ComboboxSelect>>)正在抛出一个事件。
闭幕词
现在我们把它的基础上，布赖恩·奥克利例子程序“如何从一个类变量数据”，它采用了模型，该模型通过控制器更新每当用户需要视图中的相应操作。不幸的是，它并没有像第一次打算那样利用Observer类，但是当我找到一个令人满意的解决方案时，我会继续研究并更新它。
你的问题很难理解。我建议删除“编辑”和“重新编辑”和“重新编辑”部分。我不在乎你编辑过多少次。只是重申整个问题而不是追加附录。你可以删除问题中3/4的单词，并且仍然可以解决问题。 –