# 設置下載進度條
tk.Label(window, text='下載進度:').place(x=40, y=80)
canvas = tk.Canvas(window, width=600, height=16, bg="white")
canvas.place(x=20, y=90)
# 下載按鈕函數
def usr_download():
  response = session.get(url_str, headers=headers2, cookies=cookies_xxx, verify=False, stream=True) # stream=True表示請求成功后并不會立即開始下載，而是在調用iter_content方法之后才會開始下載
  chunk_size = 40960 # 設置每次下載的塊大小
  content_size = int(m4a.headers['content-length']) # 從返回的response的headers中獲取文件大小
  # 填充進度條
  fill_line = canvas.create_rectangle(1.5, 1.5, 0, 23, width=0, fill="green")
  raise_data = 600 / (content_size/chunk_size)  # 增量大小，600為進度條的長度
 
  # 將下載的數據寫入文件
  with open(title + '.m4a', 'wb') as f:
     n = 0
     for data in response.iter_content(chunk_size=chunk_size): # 在循環讀取文件時，刷新進度條 
       f.write(data)
       n = n + raise_data  
       canvas.coords(fill_line, (0, 0, n, 60))
       window.update()
 
# 清空進度條
def clean_progressbar():
  # 清空進度條
  fill_line = canvas.create_rectangle(1.5, 1.5, 0, 23, width=0, fill="white")
  x = 500 # 未知變量，可更改
  n = 600 / x # 465是矩形填充滿的次數
 
  for t in range(x):
    n = n + 600 / x
    # 以矩形的長度作為變量值更新
    canvas.coords(fill_line, (0, 0, n, 60))
    window.update()
 
# 下載按鈕
btn_download = tk.Button(window, text='開始下載', command=usr_download)
btn_download.place(x=600, y=28)