tkinter 之 title entry button

import tkinter as tk
mainwin=tk.Tk()
vId=tk.StringVar()
mainwin.geometry("400x200")
mainwin.title("銷售系統")

lbe01=tk.Label(mainwin,text="編號")  #label
lbe01.grid(row=0,column=0)

texPid=tk.Entry(mainwin,width=15,textvariable=vId)  #輸入
texPid.grid(row=0,column=1)

btnCreate=tk.Button(mainwin,text="產品新增") #
btnCreate.grid(row=0,column=2)
mainwin.mainloop()