1、说明
用于等待按钮。当用户按下按钮时,句子将被执行并获得返回值。
2、语法
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retval = cv2.waitKey([delay])
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- Retval:表示返回值;
- Delay:键触发的时间,单位为ms。
3、实例
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import cv2
lena = cv2.imread( "D:\pmjcv\lena.bmp" )
cv2.namedWindow( "lesson" )
cv2.imshow( "lesson" ,lena)
key = cv2.waitKey()
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实例扩展:
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# 需要导入模块: import cv2 [as 别名]
# 或者: from cv2 import waitKeyEx [as 别名]
def on_process_messages( self , sleep_time = 0 ):
has_windows = False
has_capture_keys = False
if len ( self .named_windows) ! = 0 :
has_windows = True
if len ( self .capture_keys_windows) ! = 0 :
has_capture_keys = True
if has_windows or has_capture_keys:
wait_key_time = max ( 1 , int (sleep_time * 1000 ) )
ord_key = cv2.waitKeyEx(wait_key_time)
shift_pressed = False
if ord_key ! = - 1 :
chr_key = chr (ord_key) if ord_key < = 255 else chr ( 0 )
if chr_key > = 'A' and chr_key < = 'Z' :
shift_pressed = True
ord_key + = 32
elif chr_key = = '?' :
shift_pressed = True
ord_key = ord ( '/' )
elif chr_key = = '<' :
shift_pressed = True
ord_key = ord ( ',' )
elif chr_key = = '>' :
shift_pressed = True
ord_key = ord ( '.' )
else :
if sleep_time ! = 0 :
time.sleep(sleep_time)
if has_capture_keys and ord_key ! = - 1 :
self .add_key_event ( self .focus_wnd_name, ord_key, False , False , shift_pressed)
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