在 Tkinter 的类之间传递值

Question

我正在开发一个小型 GUI，以从我们的 CMDB 查询信息以显示给用户。我遇到的麻烦是在一个类中的事件发生（按钮）之后，我想更新另一个类中的组合框。我想我应该使用 tk.StringVar() 来传递列表，但是组合框只显示一个 'PC_VAR#' 值并且不会更新。请问有人可以帮忙吗？

#!/usr/bin/python

import Tkinter as tk
import ttk
import signal


class LoginUI:
    def __init__(self, frame):
        self.frame = frame

        # Set default list entry
        self.dc_list = tk.StringVar()
        self.dc_list.set(['Login first'])

        # Add a button to log in
        self.button = tk.Button(self.frame, text='Login', command=self.change_combobox)
        self.button.grid(column=0, row=0, pady=5)

    def change_combobox(self):
        # Change combobox values
        dc_list = ['Site_1', 'Site_2', 'Site_3']
        self.dc_list.set(dc_list)


class QueryUI:
    def __init__(self, frame, dc_list):
        self.frame = frame
        self.dc = tk.StringVar()
        self.dc_list = tk.StringVar()
        self.dc_list.set(dc_list)

        # Create site combobox
        tk.Label(self.frame, text='Site:').grid(column=0, row=0, sticky="w")
        self.dc_combobox = ttk.Combobox(
            self.frame,
            textvariable=self.dc,
            width=20,
            state='readonly'
        )
        self.dc_combobox['values'] = self.dc_list.get()
        self.dc_combobox.grid(column=1, row=0, sticky="w")


class App:
    def __init__(self, root):
        self.root = root
        self.root.title('Logging Handler')
        self.root.columnconfigure(0, weight=1)
        self.root.rowconfigure(0, weight=1)

        # Create the left frame panels
        left_frame = tk.Frame(self.root, padx=5, pady=5)
        login_frame = tk.LabelFrame(left_frame, text="Login", borderwidth=2, relief="groove", padx=5, pady=5)
        query_frame = tk.LabelFrame(left_frame, text="Query", borderwidth=2, relief="groove", padx=5, pady=5)

        # Align frames
        left_frame.grid(row=0, column=0, sticky="nw")
        login_frame.grid(row=0, column=0, pady=5, sticky="nw")
        query_frame.grid(row=1, column=0, pady=5, sticky="nw")

        # Initialize all frames
        self.login = LoginUI(login_frame)
        self.query = QueryUI(query_frame, self.login.dc_list)
        self.root.protocol('WM_DELETE_WINDOW', self.quit)
        self.root.bind('<Control-q>', self.quit)
        signal.signal(signal.SIGINT, self.quit)

    def quit(self, *args):
        self.root.destroy()


def main():
    root = tk.Tk()
    app = App(root)
    app.root.mainloop()


if __name__ == '__main__':
    main()

Answer 1

我在这里要做的是将控制类（应用程序）传递给更新组合框所需的类。这样我们可以在以后需要时与之交互。通过将App 的self 传递给LoginUI，我们可以在LoginUI 中与App 的类属性和方法进行交互。这使得更新组合框变得很简单。

也就是说你真的不需要所有的 StringVars。只需将列表作为列表过去，您就可以开始了。

import Tkinter as tk
import ttk
import signal


class LoginUI:
    def __init__(self, controller, frame):
        self.controller = controller
        self.frame = frame
        self.dc_list = ['Login first']
        self.button = tk.Button(self.frame, text='Login', command=self.change_combobox)
        self.button.grid(column=0, row=0, pady=5)

    def change_combobox(self):
        self.controller.query.dc_combobox['values'] = ['Site_1', 'Site_2', 'Site_3']
        self.controller.query.dc.set('Site_1')


class QueryUI:
    def __init__(self, frame, dc_list):
        self.frame = frame
        self.dc = tk.StringVar()
        tk.Label(self.frame, text='Site:').grid(column=0, row=0, sticky="w")
        self.dc_combobox = ttk.Combobox(self.frame, textvariable=self.dc, width=20, state='readonly')
        self.dc_combobox['values'] = dc_list
        self.dc_combobox.grid(column=1, row=0, sticky="w")


class App:
    def __init__(self, root):
        self.root = root
        self.root.title('Logging Handler')
        self.root.columnconfigure(0, weight=1)
        self.root.rowconfigure(0, weight=1)

        left_frame = tk.Frame(self.root, padx=5, pady=5)
        login_frame = tk.LabelFrame(left_frame, text="Login", borderwidth=2, relief="groove", padx=5, pady=5)
        query_frame = tk.LabelFrame(left_frame, text="Query", borderwidth=2, relief="groove", padx=5, pady=5)
        left_frame.grid(row=0, column=0, sticky="nw")
        login_frame.grid(row=0, column=0, pady=5, sticky="nw")
        query_frame.grid(row=1, column=0, pady=5, sticky="nw")
        self.login = LoginUI(self, login_frame)
        self.query = QueryUI(query_frame, self.login.dc_list)
        self.root.protocol('WM_DELETE_WINDOW', self.quit)
        self.root.bind('<Control-q>', self.quit)
        signal.signal(signal.SIGINT, self.quit)

    def quit(self, *args):
        self.root.destroy()


if __name__ == '__main__':
    root = tk.Tk()
    app = App(root)
    app.root.mainloop()