在tkinter中切换两帧

Question

我已经构建了我的前几个脚本,它们上面有一个很好的小GUI,正如教程向我展示的那样,但它们都没有说明如何处理更复杂的程序.

如果你有一个带有"开始菜单"的东西,对于你的开始屏幕,并且在用户选择后你移动到程序的不同部分并适当地重新绘制屏幕,​​这样做的优雅方式是什么？

一个只是.destroy()'开始菜单'框架,然后创建一个新的填充小部件的另一个部分？当他们按下后退按钮时反转这个过程？

Answer 1

一种方法是将框架堆叠在一起,然后您可以简单地在堆叠顺序中将一个框架上下移动.顶部的那个将是可见的.如果所有帧都具有相同的大小,则效果最佳,但只需稍加工作即可使其适用于任何大小的帧.

注意:为此,页面的所有小部件都必须具有该页面(即:)self或后代作为父级(或主页,具体取决于您喜欢的术语).

这里有一个人为的例子来向您展示一般概念:

import tkinter as tk                # python 3
from tkinter import font  as tkfont # python 3
#import Tkinter as tk     # python 2
#import tkFont as tkfont  # python 2

class SampleApp(tk.Tk):

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)

        self.title_font = tkfont.Font(family='Helvetica', size=18, weight="bold", slant="italic")

        # 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 = 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 (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")

        self.show_frame("StartPage")

    def show_frame(self, page_name):
        '''Show a frame for the given page name'''
        frame = self.frames[page_name]
        frame.tkraise()


class StartPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        label = tk.Label(self, text="This is the start page", font=controller.title_font)
        label.pack(side="top", fill="x", pady=10)

        button1 = tk.Button(self, text="Go to Page One",
                            command=lambda: controller.show_frame("PageOne"))
        button2 = tk.Button(self, text="Go to Page Two",
                            command=lambda: controller.show_frame("PageTwo"))
        button1.pack()
        button2.pack()


class PageOne(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        label = tk.Label(self, text="This is page 1", font=controller.title_font)
        label.pack(side="top", fill="x", pady=10)
        button = tk.Button(self, text="Go to the start page",
                           command=lambda: controller.show_frame("StartPage"))
        button.pack()


class PageTwo(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        label = tk.Label(self, text="This is page 2", font=controller.title_font)
        label.pack(side="top", fill="x", pady=10)
        button = tk.Button(self, text="Go to the start page",
                           command=lambda: controller.show_frame("StartPage"))
        button.pack()


if __name__ == "__main__":
    app = SampleApp()
    app.mainloop()

如果您发现在类中创建实例的概念令人困惑,或者在构造期间不同页面需要不同的参数,则可以单独显式调用每个类.循环主要用于说明每个类是相同的.

例如,要单独创建类,可以删除循环(for F in (StartPage, ...)使用以下代码:

self.frames["StartPage"] = StartPage(parent=container, controller=self)
self.frames["PageOne"] = PageOne(parent=container, controller=self)
self.frames["PageTwo"] = PageTwo(parent=container, controller=self)

self.frames["StartPage"].grid(row=0, column=0, sticky="nsew")
self.frames["PageOne"].grid(row=0, column=0, sticky="nsew")
self.frames["PageTwo"].grid(row=0, column=0, sticky="nsew")

随着时间的推移,人们已经使用此代码(或复制此代码的在线教程)作为起点询问了其他问题.您可能想要阅读这些问题的答案:

• 了解Tkinter中的父级和控制器__init__
• Tkinter的!了解如何切换帧
• 如何从类中获取可变数据
• 将功能从Tkinter帧调用到另一个
• 如何从tkinter中的不同类访问变量？
• 如何在每次在tkinter中显示帧时运行一个方法
• Tkinter框架调整大小
• Tkinter在单独的文件中有页面代码
• 按下按钮刷新tkinter框架

Answer 2

这是另一个简单的答案,但不使用类.

from tkinter import *


def raise_frame(frame):
    frame.tkraise()

root = Tk()

f1 = Frame(root)
f2 = Frame(root)
f3 = Frame(root)
f4 = Frame(root)

for frame in (f1, f2, f3, f4):
    frame.grid(row=0, column=0, sticky='news')

Button(f1, text='Go to frame 2', command=lambda:raise_frame(f2)).pack()
Label(f1, text='FRAME 1').pack()

Label(f2, text='FRAME 2').pack()
Button(f2, text='Go to frame 3', command=lambda:raise_frame(f3)).pack()

Label(f3, text='FRAME 3').pack(side='left')
Button(f3, text='Go to frame 4', command=lambda:raise_frame(f4)).pack(side='left')

Label(f4, text='FRAME 4').pack()
Button(f4, text='Goto to frame 1', command=lambda:raise_frame(f1)).pack()

raise_frame(f1)
root.mainloop()

Answer 3

要切换帧tkinter,请销毁旧帧,然后将其替换为新帧.

虽然Bryan Oakley的框架堆叠是一个聪明的解决方案,但它可以让每一帧都保持活跃状态​​.这有一个意想不到的副作用,让用户可以通过按下从其他框架中选择小部件Tab.

我已经修改了Bryan的答案,在更换之前销毁旧框架.作为额外的好处,这消除了对container对象的需要,并允许您使用任何泛型Frame类.

# Multi-frame tkinter application v2.3
import tkinter as tk

class SampleApp(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self._frame = None
        self.switch_frame(StartPage)

    def switch_frame(self, frame_class):
        """Destroys current frame and replaces it with a new one."""
        new_frame = frame_class(self)
        if self._frame is not None:
            self._frame.destroy()
        self._frame = new_frame
        self._frame.pack()

class StartPage(tk.Frame):
    def __init__(self, master):
        tk.Frame.__init__(self, master)
        tk.Label(self, text="This is the start page").pack(side="top", fill="x", pady=10)
        tk.Button(self, text="Open page one",
                  command=lambda: master.switch_frame(PageOne)).pack()
        tk.Button(self, text="Open page two",
                  command=lambda: master.switch_frame(PageTwo)).pack()

class PageOne(tk.Frame):
    def __init__(self, master):
        tk.Frame.__init__(self, master)
        tk.Label(self, text="This is page one").pack(side="top", fill="x", pady=10)
        tk.Button(self, text="Return to start page",
                  command=lambda: master.switch_frame(StartPage)).pack()

class PageTwo(tk.Frame):
    def __init__(self, master):
        tk.Frame.__init__(self, master)
        tk.Label(self, text="This is page two").pack(side="top", fill="x", pady=10)
        tk.Button(self, text="Return to start page",
                  command=lambda: master.switch_frame(StartPage)).pack()

if __name__ == "__main__":
    app = SampleApp()
    app.mainloop()

说明

switch_frame()通过接受任何实现的Class对象来工作Frame.然后,该函数创建一个新框架以替换旧框架.

• 删除旧的(_frame如果存在),然后将其替换为新帧.
• 添加的其他帧.pack()(如菜单栏)将不受影响.
• 可以与任何实现的类一起使用tkinter.Frame.
• 窗口会自动调整大小以适应新内容

版本历史

v2.3

- Pack buttons and labels as they are initialized

v2.2

- Initialize `_frame` as `None`.
- Check if `_frame` is `None` before calling `.destroy()`.

v2.1.1

- Remove type-hinting for backwards compatibility with Python 3.4.

v2.1

- Add type-hinting for `frame_class`.

v2.0

- Remove extraneous `container` frame.
    - Application now works with any generic `tkinter.frame` instance.
- Remove `controller` argument from frame classes.
    - Frame switching is now done with `master.switch_frame()`.

v1.6

- Check if frame attribute exists before destroying it.
- Use `switch_frame()` to set first frame.

v1.5

  - Revert 'Initialize new `_frame` after old `_frame` is destroyed'.
      - Initializing the frame before calling `.destroy()` results
        in a smoother visual transition.

v1.4

- Pack frames in `switch_frame()`.
- Initialize new `_frame` after old `_frame` is destroyed.
    - Remove `new_frame` variable.

v1.3

- Rename `parent` to `master` for consistency with base `Frame` class.

v1.2

- Remove `main()` function.

v1.1

- Rename `frame` to `_frame`.
    - Naming implies variable should be private.
- Create new frame before destroying old frame.

v1.0

- Initial version.