Python Tkinter：將帶有變量的函數傳遞到調用該函數的按鈕中，並將var傳遞到入口表單中

Question

這是我第一次在這里提問，請耐心等待。 我正在嘗試制作一個 GUI，它將任何新的/更新的文本文件從一個文件傳輸到另一個文件。 GUI 還應顯示上次文件傳輸的日期作為參考。 我的主要問題是我抓取文件的功能會自動運行，而不是按下按鈕。 我該怎么做才能將其修復到僅在按下相應按鈕時才運行的位置。

import sqlite3
from tkinter import *
from tkinter import filedialog
import tkinter as tk
import datetime
from datetime import datetime, timedelta
import os
import shutil

databaseName = 'last_check.sqlite'
#make table
def datetime_tbl():
    conn = sqlite3.connect(databaseName)
    c = conn.cursor()
    c.execute('CREATE TABLE IF NOT EXISTS datetime_tbl(datestamp TEXT)');
    c.close()
    conn.close()
#grab entry from ui
def data_entry():
    conn = sqlite3.connect(databaseName)
    c = conn.cursor()
    c.execute("INSERT INTO datetime_tbl (datestamp) VALUES (?)", 
(str(datetime.now()),))
    conn.commit()
    conn.close()

#this grabs file transfer from tbl for entry form              
def generatelasttransfer():
    conn = sqlite3.connect(databaseName)
    c = conn.cursor()
    global transfer
    transfer = c.execute("""SELECT MAX(datestamp) FROM datetime_tbl ORDER BY 
        datestamp DESC LIMIT 1""").fetchall() 
    #print(transfer)#testing
    return(transfer)
    c.close()
    #conn.close()    

def ui(root):
    transfer = StringVar()
    transfer.set(generatelasttransfer())
    src_filename = StringVar()
    src_filename.set(src_files())
    des_filename = StringVar()
    des_filename.set(des_files())

    #btn for main file transfer 
    btn_ck = tk.Button(text='File Transfer',command= f_transfer).grid(row = 
        7, column = 2, padx = 5, pady = 5)
    #btns for src and des files
    btn_src = tk.Button(text='Choose file to send out',command= 
        src_files).grid(row = 2, column = 2, padx = 5, pady = 5)
    btn_des = tk.Button(text='Choose file to send to',command= 
        des_files).grid(row = 2, column = 4, padx = 5, pady = 5)

    tk.Entry(text= src_filename).grid(row = 3, column = 2, padx = 15, pady = 5)
    tk.Entry(text= des_filename).grid(row = 3, column = 4, padx = 15, pady = 5)
    tk.Entry(root, textvariable = transfer, width=28).grid(row = 7,column = 4,padx = 7,pady = 7)

def src_files():
    global src_filename
    src_filename =  filedialog.askdirectory()
    return src_filename
def des_files():
    global des_filename
    des_filename =  filedialog.askdirectory()
    return des_filename
#file transfer
def f_transfer():
    for root,dirs,files in os.walk(src_filename):
        for file_name in files:
            now = datetime.now()
            before = now - timedelta(hours=24)
            files = os.path.join(src_filename, file_name)
            mod_time = datetime.fromtimestamp(os.path.getmtime(files))
            if mod_time > before:
                shutil.move(os.path.join(src_filename, file_name), 
                    des_filename)
                data_entry()  

if __name__ == '__main__':
    datetime_tbl()
    root = Tk()
    root.mainloop
    ui(root)

Answer 1

閉包在這里非常方便，因為這里的數據容器（ src_filename ， dest_filename ）是可變的StringVar對象。

首先， src_files()和des_files()可以重構為單個函數。 讓我們不再使用這些全局變量。

def get_file(src_filename):
    def wrap():
        src_filename.set(filedialog.askdirectory())
    return wrap

這將作為按鈕命令傳遞，如下所示：

btn_src = tk.Button(
    text='Choose file to send out',
    command=get_file(src_filename)
).grid(
    row=2, column=2, padx=5, pady=5
)

btn_des = tk.Button(
    text='Choose file to send to',
    command=get_file(des_filename)
).grid(row=2, column=4, padx=5, pady=5)

f_transfer還將關閉src_filename和des_filename因為它使用這兩個名稱。

def f_transfer(src_filename, des_filename):
    def wrap():
        _src_filename, _des_filename = src_filename.get(), des_filename.get()

        for root,dirs,files in os.walk(_src_filename):
            for file_name in files:
                now = datetime.now()
                before = now - timedelta(hours=24)
                files = os.path.join(_src_filename, file_name)
                mod_time = datetime.fromtimestamp(os.path.getmtime(files))
                if mod_time > before:
                    shutil.move(
                        os.path.join(_src_filename, file_name), 
                        _des_filename
                    )
                    data_entry()
    return wrap

在將它作為命令傳遞給f_transfer之前，我們將把這兩個名稱綁定到btn_ck 。

btn_ck = tk.Button(
    text='File Transfer',
    command=f_transfer(src_filename, des_filename)
).grid(
    row=7, column=2, padx=5, pady=5
)

獎勵：我們需要在設置 GUI 組件后運行主循環等等！

if __name__ == '__main__':
    datetime_tbl()
    root = Tk()
    ui(root)
    root.mainloop()