在 tkinter 中的两个帧之间切换

Question

我已经用一个漂亮的小 GUI 构建了我的前几个脚本，正如教程向我展示的那样，但它们都没有解决如何处理更复杂的程序。

如果您有一个带有“开始菜单”的东西，对于您的打开屏幕，并且在用户选择后您移动到程序的不同部分并适当地重新绘制屏幕，​​那么这样做的优雅方式是什么？

是否只是.destroy() '开始菜单' 框架，然后创建一个新的，其中填充了另一部分的小部件？并在他们按下返回按钮时反转这个过程？

Answer 1

一种方法是将框架堆叠在一起，然后您可以简单地按照堆叠顺序将一个框架提升到另一个之上。顶部的那个将是可见的。如果所有框架的大小都相同，则此方法效果最佳，但只需稍加工作即可使其适用于任何大小的框架。

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（或主，取决于您使用的术语）更喜欢）。

这里有一个人为的例子来向你展示一般概念：

try:
    import tkinter as tk                # python 3
    from tkinter import font as tkfont  # python 3
except ImportError:
    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，或者如果不同的页面在构建过程中需要不同的参数，您可以显式地分别调用每个类。该循环主要用于说明每个类都是相同的这一点。

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

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，人们使用此代码（或复制此代码的在线教程）作为起点提出了其他问题。您可能想阅读以下问题的答案：

• Understanding parent and controller in Tkinter __init__
• Tkinter! Understanding how to switch frames
• How to get variable data from a class
• Calling functions from a Tkinter Frame to another
• How to access variables from different classes in tkinter?
• How would I make a method which is run every time a frame is shown in tkinter
• Tkinter Frame Resize
• Tkinter have code for pages in separate files
• Refresh a tkinter frame on button press

Answer 2

这是另一个简单的答案，但没有使用类。

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

注意：According to JDN96，下面的答案可能会导致memory leak通过反复销毁和重新创建框架。但是，我自己并没有测试来验证这一点。

在tkinter 中切换框架的一种方法是销毁旧框架，然后用新框架替换它。

我已修改Bryan Oakley's 答案以在更换旧框架之前将其销毁。作为额外的好处，这消除了对 container 对象的需要，并允许您使用任何通用的 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 Frame 的 Class 对象来工作。然后该函数创建一个新框架来替换旧框架。

• 删除旧的_frame（如果存在），然后用新框架替换它。
• 使用.pack() 添加的其他框架（例如菜单栏）将不受影响。
• 可与任何实现tkinter.Frame 的类一起使用。
• 窗口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.

Answer 4

如果您使用的是pack 几何管理器，也许更直观的解决方案是使用pack_forget 方法隐藏/取消隐藏框架。

这是一个简单的例子。

import tkinter as tk


class App:
    def __init__(self, root=None):
        self.root = root
        self.frame = tk.Frame(self.root)
        self.frame.pack()
        tk.Label(self.frame, text='Main page').pack()
        tk.Button(self.frame, text='Go to Page 1',
                  command=self.make_page_1).pack()
        self.page_1 = Page_1(master=self.root, app=self)

    def main_page(self):
        self.frame.pack()

    def make_page_1(self):
        self.frame.pack_forget()
        self.page_1.start_page()


class Page_1:
    def __init__(self, master=None, app=None):
        self.master = master
        self.app = app
        self.frame = tk.Frame(self.master)
        tk.Label(self.frame, text='Page 1').pack()
        tk.Button(self.frame, text='Go back', command=self.go_back).pack()

    def start_page(self):
        self.frame.pack()

    def go_back(self):
        self.frame.pack_forget()
        self.app.main_page()


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