我正在使用 tkinter 在 python 中為 brainf*ck 制作一個(gè) ide，我正在添加一個(gè)最近的項(xiàng)目部分，但是當(dāng)我放置按鈕時(shí)，它們不會(huì)出現(xiàn)在屏幕上。這是代碼Scene：from tkinter import *from tkinter import filedialog as Fileimport tkinter as tkclass HoverButton(tk.Button):    def __init__(self, master, **kw):        tk.Button.__init__(self, master=master, **kw)        self.defaultBackground = "#5d5d5d"        self['background'] = self.defaultBackground        self['activebackground'] = "#6d6d6d"        self.bind("<Enter>", self.on_enter)        self.bind("<Leave>", self.on_leave)    def on_enter(self, e):        self['background'] = "#6d6d6d"    def on_leave(self, e):        self['background'] = self.defaultBackgroundclass ProjectPage(Frame):    def __init__(self, master, projects=[]):        super().__init__(master)        self.projects = projects        self.buttons = []        self.mstr = self.master.master        self.title = "PesolIde: Projets"        self.width = 800        self.height = 500        self.color = "#4d4d4d"        self.projectFrame = tk.Frame(self.mstr,width=800,height=50,bg="#5d5d5d")        self.newProject = HoverButton(self.mstr,text="New Project", height=1, bg="#6d6d6d")        self.openProject = HoverButton(self.mstr,text="Open Project", height=1,bg="#6d6d6d", command=OpenAsk)        self.projectdisplay = tk.Frame(self.mstr, width=700, height=300, bg="#5d5d5d", highlightbackground="black", highlightthickness=1)        for i in range(len(self.projects)):            self.buttons.append(HoverButton(master, text=self.projects[i].split(':')[0], width=50, height=1))            if len(self.buttons)>=40:                break        self.loaded = False    def show(self):        self.projectFrame.place(x=0, y=0)        self.newProject.place(x=20, y=10)        self.openProject.place(x=120, y=10)        self.projectdisplay.place(x=50,y=100)        self.y = 100當(dāng)我在文件中創(chuàng)建類HoverButton外部時(shí)，它會(huì)按預(yù)期顯示，但在直接從主文件的類中初始化時(shí)不會(huì)出現(xiàn)。ProjectPageProjectPageProjectPage使用左側(cè)代碼從類外運(yùn)行的輸出：