Python OpenCV cv2.WaitKey（）和Windows 10

Question

我做了一个小的python程序来从屏幕上捕获图像。它被设计为在Esc或＆＃39; a＆＃39;键被按下了。它按照编程捕获图像，但是当我按下Esc或＆＃39; a＆＃39;键。我的操作系统是Windows 10，我使用的是Python 3.6.4（Anaconda）。这是代码：

import cv2
import mss
from PIL import Image

#Creates an endless loop for high-speed image acquisition...
while 1:
    with mss.mss() as sct:
        #Get raw pixels from the screen
        sct_img = sct.grab(sct.monitors[1])

        #Create the Image
        img = Image.frombytes('RGB', sct_img.size, sct_img.bgra, 'raw', 'BGRX')

        #Show the Image
        cv2.imshow('test', np.array(img))

        #Kill-switch: press the 'Esc' or 'a' keys to exit the program
        if (cv2.waitKey(33) == 27) or (cv2.waitKey(33) == ord('a')):
            cv2.destroyAllWindows()
            break

我哪里错了？