我想從網絡攝像頭閱讀視頻，幫助python上的opencv，但我有下一個錯誤：'NoneType' object has no attribute 'shape'.在控制臺中，我有：[ WARN:0] videoio(MSMF): can't grab frame. Error: -2147483638print("starting video stream...")vs = VideoStream(src=0).start()time.sleep(2.0)while True:    frame = vs.read()    frame = imutils.resize(frame, width=600)    #'NoneType' object has no attribute 'shape'    if W is None or H is None:        (H, W) = frame.shape[:2]    cv2.imshow("Frame", frame)    key = cv2.waitKey(1) & 0xFF    if key == ord("q"):        breakcv2.destroyAllWindows()vs.stop()干草我能解決這個問題嗎？謝謝！