import tkinter as tk

def chuancan():
    print(a)

def changkuan():
    def huidiao():
        width=chang_name.get()
        height=kuan_name.get()
        #print(width)
        #print(height)
        return width,height
        chuancan()

    changkuan_window=tk.Tk()
    changkuan_window.title('长宽设置界面')
    changkuan_window.geometry('430x200')
    
    chang_name = tk.StringVar()
    chang_entry_name = tk.Entry(changkuan_window, textvariable=chang_name)
    chang_entry_name.place(x=180, y=50)

    kuan_name = tk.StringVar()
    kuan_entry_name = tk.Entry(changkuan_window, textvariable=kuan_name)
    kuan_entry_name.place(x=180, y=100)
    
    btn = tk.Button(changkuan_window, text='确定', command=huidiao)
    btn.place(x=150, y=120)
    
    tk.Label(changkuan_window, text='长：').place(x=40, y=50)
    tk.Label(changkuan_window, text='宽：').place(x=40, y=50)

a=changkuan()