Tkinter实现仅在窗口未打开时新建窗口，已打开则前置显示

要实现点击按钮时仅在窗口未打开时创建新窗口，已打开则将其前置，核心是追踪Toplevel窗口的实例状态，以下是修改后的代码：

def main():
    main_bg = "Gray"
    main_fg = "White"
    
    import tkinter as tk

    employees = []
    
    window = tk.Tk()
    window.configure(bg=main_bg)
    window.title("Business app")
    window.geometry("1100x650")

    # 初始化窗口实例变量，用于追踪Toplevel窗口状态
    random_window = None

    def open_new_window():
        nonlocal random_window
        
        # 检查窗口是否未创建或已被销毁
        if random_window is None or not random_window.winfo_exists():
            random_window = tk.Toplevel(window)
            random_window.configure(bg=main_bg)
            random_window.geometry("600x600")
            # 绑定关闭事件，重置实例变量，确保下次点击可重新创建
            def on_window_close():
                nonlocal random_window
                random_window.destroy()
                random_window = None
            random_window.protocol("WM_DELETE_WINDOW", on_window_close)
        else:
            # 将已存在的窗口前置并获取焦点
            random_window.lift()
            random_window.focus_force()

    random_button = tk.Button(window, text="Do Something", font="Times 32", bg=main_bg, fg=main_fg, command=open_new_window)
    random_button.pack()

    window.mainloop()

if __name__ == "__main__":
    main()

关键改动说明 #

• 使用nonlocal关键字让内部函数访问外部的random_window变量，实现状态追踪
• 通过winfo_exists()方法判断窗口是否已被用户关闭
• 调用lift()将窗口前置到最上层，focus_force()确保窗口获得输入焦点
• 绑定WM_DELETE_WINDOW协议，在用户关闭Toplevel窗口时重置实例变量，保证下次点击可重新创建窗口

内容的提问来源于stack exchange，提问作者Ali Alizade