Question

我正在尝试让Entry字段在新页面打开时获得焦点：

import tkinter as tk
from tkinter import *
from tkinter import ttk

class DIS(tk.Tk):

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)
        tk.Tk.iconbitmap(self, default="")
        tk.Tk.wm_title(self, "program")
        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, contactQues):
            frame = F(container, self)
            self.frames[F] = frame
            frame.grid(row = 0, column = 0, sticky = "nsew")
            self.show_frame(startPage)

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

class startPage(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        button2 = ttk.Button(self, text = "Here's a Button",
                    command=lambda: controller.show_frame(contactQues))
        button2.pack()

class contactQues(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)  
        self.controller = controller

        entry = Entry(self)
        entry.focus_force()
        entry.pack()

app = DIS()
app.mainloop()

如果我移动Entry下的startPage字段，则焦点设置正确 - 每当我将其移至contactQues时，它就会失去焦点。可能是Toplevel问题？

Answer 1

似乎tkraise()弄乱了焦点。因此，您需要在将页面提升到视图后调用它。我更新你的框架，总是在tkraise之后调用一些方法：

import tkinter as tk
from tkinter import *
from tkinter import ttk

class DIS(tk.Tk):

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)
        tk.Tk.iconbitmap(self, default="")
        tk.Tk.wm_title(self, "program")
        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, contactQues):
            frame = F(container, self)
            self.frames[F] = frame
            frame.grid(row = 0, column = 0, sticky = "nsew")
            self.show_frame(startPage)

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

class startPage(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        button2 = ttk.Button(self, text = "Here's a Button",
                    command=lambda: controller.show_frame(contactQues))
        button2.pack()

    def postupdate(self):
        pass

class contactQues(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)  
        self.controller = controller

        self.entry = Entry(self)
        self.entry.pack()

    def postupdate(self):
        self.entry.focus()

app = DIS()
app.mainloop()

如果您想避免使用不需要的postupdate()方法，可以在尝试运行之前检查它是否存在于类中。像这样：

def show_frame(self, cont):
    frame = self.frames[cont]
    frame.tkraise()
    try:
        frame.postupdate()
    except AttributeError:
        pass

Tkinter focus_set和focus_force没有按预期工作

1 个答案: