如何打印出 ttk.多个框架中的组合框选项?

Question

在我的代码中，有两个框架。在第一个中，我放入了一个"添加"按钮，该按钮将生成一个带有Combobox的新框架。这个想法是在第一帧中添加一些类似的Combobox，为不同的Combobox选择不同的选项，然后在下一帧中打印出来。但是当我在第二帧中点击Show options按钮时，它不会打印出我在第一帧中选择的选项。我该如何解决这个问题？

from tkinter import *
from tkinter import ttk
list_1 = []

class Validation_Tool(Tk):
def __init__(self, *args, **kwargs):
Tk.__init__(self, *args, **kwargs)
container = 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 (PageOne, PageTwo):
page_name = F.__name__
frame = F(parent=container, controller=self)
self.frames[page_name] = frame
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame("PageOne")
def show_frame(self, page_name):
frame = self.frames[page_name]
frame.tkraise()
def quit(self):
self.destroy()

class PageOne(Frame):
def __init__(self, parent, controller):
Frame.__init__(self, parent)
self.controller = controller
def add_compare():
global list_1
frame = Frame(self)
frame.pack()
label_1 = Label(frame, text='Options')
label_1.grid(row=0, column=0)
self.options_1 = ttk.Combobox(frame, values=['a','b','c','d','e'])
self.options_1.grid(row=1, column=0)
list_1.append(self.options_1.get())
quit_button = Button(self, text="Quit Program",
command=lambda: controller.quit())
next_button = Button(self, text="Next",
command=lambda: controller.show_frame("PageTwo"))
add_button = Button(self, text='Add', command=add_compare)
quit_button.place(relx=0.98, rely=0.98, anchor=SE)
next_button.place(relx=0.76, rely=0.98, anchor=SE)
add_button.place(relx=0.661, rely=0.98, anchor=SE)

class PageTwo(Frame):
def __init__(self, parent, controller):
Frame.__init__(self, parent)
self.controller = controller
def button():
label = Label(self, text=list_1)
label.pack()
quit_button = Button(self, text="Quit Program",
command=lambda: controller.quit())
back_button = Button(self, text="Back",
command=lambda: controller.show_frame("PageOne"))
show_button = Button(self, text='Show options', command=button)
show_button.pack()
back_button.place(relx=0.76, rely=0.98, anchor=SE)
quit_button.place(relx=0.98, rely=0.98, anchor=SE)

if __name__ == "__main__":
root = Validation_Tool()
root.geometry('400x300+430+250')
root.title("Validation Tool")
root.mainloop()

Answer 1

下面是代码的修改版本，它将在按下"下一个"时打印到目前为止选择的选项。为了防止Combobox相互干扰，保留了它们的列表和关联的StringVar。

拥有单独的StringVar可以避免在其中一个选项上选择一个选项而不是在其他选项上更改它的问题——即不同的textvar与每个选项相关联。

为了使所有选项一起收集到list_1，已经定义了一个名为selected()的回调函数，并被"绑定"到Combobox选择事件。这样，除了上述内容之外，所选选项还将附加到 全局list_1，这就是显示选项按钮显示的内容。

from tkinter import *
from tkinter import ttk
list_1 = []

class Validation_Tool(Tk):
def __init__(self, *args, **kwargs):
Tk.__init__(self, *args, **kwargs)
container = Frame(self)
container.pack(side="top", fill="both", expand=True)
container.grid_rowconfigure(0, weight=1)
container.grid_columnconfigure(0, weight=1)
self.comboboxes = []  # Comboboxes created. ADDED
self.combobox_vars = []  # Vars for Comboboxes. ADDED.
self.frames = {}
for F in (PageOne, PageTwo):
page_name = F.__name__
frame = F(parent=container, controller=self)
self.frames[page_name] = frame
frame.grid(row=0, column=0, sticky="nsew")
self.show_frame("PageOne")
def show_frame(self, page_name):
frame = self.frames[page_name]
frame.tkraise()
def quit(self):
self.destroy()
class PageOne(Frame):
def __init__(self, parent, controller):
Frame.__init__(self, parent)
self.controller = controller
# Combobox event handler. ADDED
def selected(event, var):
list_1.append(var.get())  # Append Combobox option selected.
def add_compare():
frame = Frame(self)
frame.pack()
label_1 = Label(frame, text='Options')
label_1.grid(row=0, column=0)
combobox_var = StringVar()  # ADDED.
combobox = ttk.Combobox(frame, values=list('abcde'),
textvar=combobox_var)  # For each Combobox. ADDED.
combobox.grid(row=1, column=0)
combobox.bind('<<ComboboxSelected>>',  # Bind event handler.           ADDED.
lambda event, var=combobox_var: selected(event, var))  # ADDED.
self.controller.comboboxes.append(combobox)         # ADDED.
self.controller.combobox_vars.append(combobox_var)  # ADDED.
quit_button = Button(self, text="Quit Program",
command=lambda: controller.quit())
next_button = Button(self, text="Next",
command=lambda: controller.show_frame("PageTwo"))
add_button = Button(self, text='Add',
command=add_compare)
quit_button.place(relx=0.98, rely=0.98, anchor=SE)
next_button.place(relx=0.76, rely=0.98, anchor=SE)
add_button.place(relx=0.661, rely=0.98, anchor=SE)

class PageTwo(Frame):
def __init__(self, parent, controller):
Frame.__init__(self, parent)
self.controller = controller
def button():
label = Label(self, text=list_1)
label.pack()
quit_button = Button(self, text="Quit Program",
command=lambda: controller.quit())
back_button = Button(self, text="Back",
command=lambda: controller.show_frame("PageOne"))
show_button = Button(self, text='Show options', command=button)
show_button.pack()
back_button.place(relx=0.76, rely=0.98, anchor=SE)
quit_button.place(relx=0.98, rely=0.98, anchor=SE)

if __name__ == "__main__":
root = Validation_Tool()
root.geometry('400x300+430+250')
root.title("Validation Tool")
root.mainloop()