python-3.x - 更改背景颜色时打开新的 Tk 窗口

Question

我有一个包含多个框架的 GUI，每个框架都包含多个标签/输入字段。我正在尝试添加一个“设置”选项，允许用户更改所有框架和标签的背景颜色。到目前为止，我已经设法完成了这项任务，但是需要注意的是会弹出一个带有所选背景的新 Tk 窗口，而不是在当前窗口上更新。

import tkinter as tk
from tkinter import ttk
from tkinter import colorchooser


bg_hex = '#f0f0f0f0f0f0'  #default background color

def pick_color():
    global bg_hex
    bg_color = colorchooser.askcolor()
    bg_hex = bg_color[1]
    Master().update()
    print(bg_hex)


class Master(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 (HomePage, PageOne, PageTwo, Settings):        
            frame = F(container, self)
            self.frames[F] = frame
            frame.config(bg = bg_hex)
            frame.grid(row=0, column=0, sticky='nsew')
        self.show_frame(HomePage)

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



class HomePage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        label = tk.Label(self, text='Home Page', font=('Verdana', 12), bg=bg_hex)
        label.pack(pady=5)
        button1 = tk.Button(self, text='Page One', command=lambda: controller.show_frame(PageOne))
        button1.pack(pady=5, ipadx=2)
        button2 = tk.Button(self, text='Page Two', command=lambda: controller.show_frame(PageTwo))
        button2.pack(pady=5)
        button3 = tk.Button(self, text='Settings', command=lambda: controller.show_frame(Settings))
        button3.pack(side='bottom', pady=10)

class PageOne(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        tk.Label(self, text='Page One', font='Verdana 14 bold underline', bg=bg_hex).grid(row=0, columnspan=2, pady=5)
        button1 = tk.Button(self, text='Back to Home', command=lambda: controller.show_frame(HomePage))
        button1.grid()


class PageTwo(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        tk.Label(self, text='Page Two', font='Verdana 14 bold underline', bg=bg_hex).grid(row=0, columnspan=2,pady=5)
        button1 = tk.Button(self, text='Back to Home', command=lambda: controller.show_frame(HomePage))
        button1.grid()

class Settings(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        tk.Label(self, text='Settings', font='Verdana 14 bold underline', bg=bg_hex).grid(row=0, columnspan=2,pady=5)
        button1 = tk.Button(self, text='Back to Home', command=lambda: controller.show_frame(HomePage))
        button1.grid() 
        button2 = tk.Button(self, text='Choose Background', command= pick_color)
        button2.grid()

Master().mainloop()

运行代码块时不会发生错误，但是当您选择“选择背景”按钮并选择一种颜色时，会打开一个带有所选背景颜色的新 Tk 窗口，而不是更新当前的 Tk 窗口。

**更新代码以反映没有全局变量，希望它可以帮助其他人。

我self.controller = controller在每个 Frame 类下添加，组合成 1 个函数pick_color并color_update放在 Tk 类下。

def pick_color_bg(self):
    bg_color = colorchooser.askcolor()
    bg_hex = bg_color[1]
    # Loop through pages and contained widgets and set color
    for cls, obj in self.frames.items():
        obj.config(bg=bg_hex)   # Set frame bg color
        for widget in obj.winfo_children():
            if '!label' in str(widget):
                widget.config(bg=bg_hex)    # Set label bg color

最后，将 Button 命令更改为command=self.controller.pick_color_bg. 通过这些更改，我能够消除对全局变量的需求。

标签： python-3.xtkinter

Answer 1

在函数pick_color()中，您创建一个Tk()获取新颜色的新实例：

Master().update()   # Creates a new root window!

要更改现有根窗口的颜色，您必须保存对它的引用。此外，您还必须在类中编写一个Master()更新背景颜色的函数。调用时颜色不会自动更新update()，您必须为每个帧配置 bg 颜色。

多一点

我无法在不重写代码的情况下阅读您的代码。您使用Master实例化根窗口的类的名称。我会称它为Application或类似名称，因为名称master通常表示“主服务器”或“父服务器”中的主服务器。您还可以使用frame通常是框架名称的 name 作为不同页面类实例（HomePage，...等）的名称。这使得阅读变得困难。就像用红色字母写的蓝色这个词。

我会用更具描述性的名称重写它，这样更容易掌握。那么问题将更容易发现和纠正。

甚至更多

花了我一段时间，但这里有一个示例，说明它如何通过细微的更改来工作：

import tkinter as tk
from tkinter import ttk
from tkinter import colorchooser


bg_hex = '#f0f0f0f0f0f0'  #default background color

def pick_color():
    global bg_hex
    bg_color = colorchooser.askcolor()
    bg_hex = bg_color[1]
    root.update_color()     # Call function for updating color
    print(bg_hex)


class Master(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 (HomePage, PageOne, PageTwo, Settings):        
            frame = F(container, self)
            self.frames[F] = frame
            frame.config(bg = bg_hex)
            frame.grid(row=0, column=0, sticky='nsew')
        self.show_frame(HomePage)

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

    def update_color(self):
        # Loop through pages and contained widgets and set color
        for cls, obj in self.frames.items():
            obj.config(bg=bg_hex)   # Set frame bg color
            for widget in obj.winfo_children():
                if '!label' in str(widget):
                    widget.config(bg=bg_hex)    # Set label bg color



class HomePage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        label = tk.Label(self, text='Home Page', font=('Verdana', 12), bg=bg_hex)
        label.pack(pady=5)
        button1 = tk.Button(self, text='Page One', command=lambda: controller.show_frame(PageOne))
        button1.pack(pady=5, ipadx=2)
        button2 = tk.Button(self, text='Page Two', command=lambda: controller.show_frame(PageTwo))
        button2.pack(pady=5)
        button3 = tk.Button(self, text='Settings', command=lambda: controller.show_frame(Settings))
        button3.pack(side='bottom', pady=10)

class PageOne(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        tk.Label(self, text='Page One', font='Verdana 14 bold underline', bg=bg_hex).grid(row=0, columnspan=2, pady=5)
        button1 = tk.Button(self, text='Back to Home', command=lambda: controller.show_frame(HomePage))
        button1.grid()


class PageTwo(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        tk.Label(self, text='Page Two', font='Verdana 14 bold underline', bg=bg_hex).grid(row=0, columnspan=2,pady=5)
        button1 = tk.Button(self, text='Back to Home', command=lambda: controller.show_frame(HomePage))
        button1.grid()

class Settings(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        tk.Label(self, text='Settings', font='Verdana 14 bold underline', bg=bg_hex).grid(row=0, columnspan=2,pady=5)
        button1 = tk.Button(self, text='Back to Home', command=lambda: controller.show_frame(HomePage))
        button1.grid() 
        button2 = tk.Button(self, text='Choose Background', command= pick_color)
        button2.grid()

root = Master()     # Save a reference to the root window
root.mainloop()

我建议不要通过全局范围内的函数来改变颜色。我认为它会更好地作为Master()类的功能。那么你就不必使用全局变量了。