cv2.waitKey(0) 不要等待

Question

key = cv2.waitKey(0)
print(key)
>>>-1

I have known that "cv2.waitKey(0)" wait and code does nothing until any key is pressed.

how can I make "cv2.waitKey(0)" work??

Answer 1

from the doc cv2.waitKey(delay) waits for delay milliseconds and also, The function only works if there is at least one HighGUI window created and the window is active.

It returns the code of the pressed key or -1 if no key was pressed before the specified time had elapsed.

You didn't press anything. that's why you get the -1