Python Tkinter为特定样式调整所有ttkbootstrap或ttk Button填充的大小，适用于所有主题

主要原因是这部分和配置tb.Style()内的setup_ui().这意味着你为danger.TButton设置的配置只与tb.Style()的实例相关联，所以，当你试图改变你的主题时，ttkbootstrap会在内部创建一个新的实例tb.Style()，而你的自定义配置不会延续到这个新实例.

danger = tb.Style()
danger.configure('danger.TButton', padding=0) # Why does this only apply to the first theme?

通过在tb.Style()的主实例上直接配置danger.TButton，您的自定义配置将在所有主题中一致地apply. 以下是您代码的解决方案:

import tkinter as tk
from tkinter import ttk
import ttkbootstrap as tb

def change_theme(theme, style):style.theme_use(theme.lower().replace(" ", ""))

def display_text(label_text, entry_text):label_text.set(entry_text.get())

def setup_ui(style):
    root = style.master

    theme_names_titlecase = [name.replace('_', ' ').title() for name in style.theme_names() if name.lower() in ['darkly', 'simplex']]
    default_theme = 'darkly'
    current_theme = tk.StringVar(value=default_theme.capitalize())
    
    theme_combo = ttk.Combobox(root, textvariable=current_theme, values=theme_names_titlecase, width=50)
    theme_combo.pack(pady=0, side=tk.TOP)
    theme_combo.bind("<<ComboboxSelected>>", lambda e: change_theme(current_theme.get(), style))

    tb.Button(root, text='Text', bootstyle='danger.TButton').pack(side=tk.TOP, padx=0, pady=0)
    tb.Button(root, text='Text', bootstyle='info.TButton').pack(side=tk.TOP, padx=0, pady=0)

    return root

if __name__ == "__main__":
    default_theme = 'darkly'
    style = tb.Style(theme=default_theme)

    style.configure('danger.TButton', padding=0) # Why does this only apply to the first theme?


    root = setup_ui(style)
    root.mainloop()