保存pdf时提示用户选择名称和位置(python)

import tkinter as tk
from tkinter import filedialog
from fpdf import FPDF

class PDFGenerator:
    def __init__(self):
        self.root = tk.Tk()
        self.root.title("PDF Generator")
        self.root.geometry("300x200")

        self.btn_generate = tk.Button(self.root, text="Generate PDF", command=self.generate_pdf)
        self.btn_generate.pack(pady=20)

    def generate_pdf(self):
        file_path = filedialog.asksaveasfilename(defaultextension=".pdf")
        if file_path:
            pdf = FPDF()
            pdf.add_page()
            pdf.set_font("Arial", size=12)
            pdf.cell(200, 10, txt="Hello, World!", ln=True)
            pdf.output(file_path)

    def run(self):
        self.root.mainloop()

if __name__ == "__main__":
    pdf_generator = PDFGenerator()
    pdf_generator.run()