CV_EVENT_FLAG_LBUTTON 中flags代表拖拽事件

#define CV_EVENT_FLAG_LBUTTON 1 左键拖曳
#define CV_EVENT_FLAG_RBUTTON 2 右键拖曳
#define CV_EVENT_FLAG_MBUTTON 4 中键拖曳
#define CV_EVENT_FLAG_CTRLKEY 8 (8~15)按Ctrl不放事件
#define CV_EVENT_FLAG_SHIFTKEY 16 (16~31)按Shift不放事件

#define CV_EVENT_FLAG_ALTKEY 32 (32~39)按Alt不放事件

import cv2
events=[i for i in dir(cv2) if 'EVENT' in i]
print(events)

 

['EVENT_FLAG_ALTKEY', 'EVENT_FLAG_CTRLKEY', 'EVENT_FLAG_LBUTTON', 'EVENT_FLAG_MBUTTON', 'EVENT_FLAG_RBUTTON', 'EVENT_FLAG_SHIFTKEY', 'EVENT_LBUTTONDBLCLK', 'EVENT_LBUTTONDOWN', 'EVENT_LBUTTONUP', 'EVENT_MBUTTONDBLCLK', 'EVENT_MBUTTONDOWN', 'EVENT_MBUTTONUP', 'EVENT_MOUSEHWHEEL', 'EVENT_MOUSEMOVE', 'EVENT_MOUSEWHEEL', 'EVENT_RBUTTONDBLCLK', 'EVENT_RBUTTONDOWN', 'EVENT_RBUTTONUP']