由于类结构，Tkinter Return 键绑定不起作用

Question

我了解如何在一个简单的框架上绑定键，但由于我以不同的方式构建我的应用程序，我似乎无法弄清楚如何绑定返回键以按下按钮或运行该按钮是有界的。我一直在网站上搜索其他人的类似问题，但我没有找到与我类似的问题。

我已将其余代码调低，并将其放在下面：

import tkinter as tk
from tkinter import *

class POS(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 (ErrorPage, MainPage):
            frame = F(container, self)
            self.frames[F] = frame
            frame.grid(row=0, column = 0, sticky = "nsew")

        self.show_frame(MainPage)

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


class MainPage(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self,parent)
        frame = tk.Frame(self)
        frame.pack(fill = BOTH)

        button = Button(frame, text = "OK", command = self.bindHello)
        button.pack(pady=5, padx=10)

        frame.bind("<Return>", self.bindHello)
        self.bind("<Return>", self.bindHello)

    def bindHello(self, event=None):
        print("HELLO1")


#Yes this doesn't do anything but I need it for the frame container as set before
class ErrorPage(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self,parent)
        frame = tk.Frame(self)
        frame.pack(fill = BOTH)

        button = Button(frame, text = "OK", command = self.bindHello)
        button.pack(pady=5, padx=10)

        frame.bind("<Return>", self.bindHello)

    def bindHello(self, event=None):
        print("HELLO2")


app = POS()
app.mainloop()

我打算按如下方式工作的简单按钮绑定：

from tkinter import *
master = Tk()

def callback(event=None):
    print("Hello " + entry.get())

entry = StringVar()
e = Entry(master, textvariable = entry, width = 15)
e.pack()

b = Button(master, text="OK", command = callback)
b.pack()
master.bind("<Return>", callback)

mainloop()

我只想有一个像上面那样的简单按钮绑定，但我似乎找不到让我的主程序工作的方法。我认为这与我构建应用程序的方式有关，但我并不完全确定。

Answer 1

在您的示例中，您绑定到窗口本身。您也可以通过多种方式在另一个中这样做：

#1 bind to page object's direct parent, which happens to be a Toplevel-like
#self.master.bind('<Return>', self.bindHello)

#2 recursively search page object's parents, and bind when it's a Toplevel-like
#self.winfo_toplevel().bind('<Return>', self.bindHello)

#3 bind to page object's inner frame's parent's parent, which happens to be a Toplevel-like
#frame.master.master.bind('<Return>', self.bindHello)

#4 recursively search page object's inner frame's parents, and bind when it's a Toplevel-like
frame.winfo_toplevel().bind('<Return>', self.bindHello)