问如何用Python在屏幕上绘制空矩形

EN

import win32gui, win32ui
from win32api import GetSystemMetrics

dc = win32gui.GetDC(0)
dcObj = win32ui.CreateDCFromHandle(dc)
hwnd = win32gui.WindowFromPoint((0,0))
monitor = (0, 0, GetSystemMetrics(0), GetSystemMetrics(1))

while True:
    m = win32gui.GetCursorPos()
    dcObj.Rectangle((m[0], m[1], m[0]+30, m[1]+30))
    win32gui.InvalidateRect(hwnd, monitor, True) # Refresh the entire monitor

import win32gui, win32ui, win32api, win32con
from win32api import GetSystemMetrics

dc = win32gui.GetDC(0)
dcObj = win32ui.CreateDCFromHandle(dc)
hwnd = win32gui.WindowFromPoint((0,0))
monitor = (0, 0, GetSystemMetrics(0), GetSystemMetrics(1))

red = win32api.RGB(255, 0, 0) # Red

past_coordinates = monitor
while True:
    m = win32gui.GetCursorPos()

    rect = win32gui.CreateRoundRectRgn(*past_coordinates, 2 , 2)
    win32gui.RedrawWindow(hwnd, past_coordinates, rect, win32con.RDW_INVALIDATE)

    for x in range(10):
        win32gui.SetPixel(dc, m[0]+x, m[1], red)
        win32gui.SetPixel(dc, m[0]+x, m[1]+10, red)
        for y in range(10):
            win32gui.SetPixel(dc, m[0], m[1]+y, red)
            win32gui.SetPixel(dc, m[0]+10, m[1]+y, red)

    past_coordinates = (m[0]-20, m[1]-20, m[0]+20, m[1]+20)

import win32api
from win32api import GetSystemMetrics
import win32con
import pygame
import win32gui
import pyautogui

pygame.init()
screen = pygame.display.set_mode((GetSystemMetrics(0), GetSystemMetrics(1)), pygame.FULLSCREEN, pygame.NOFRAME) # For borderless, use pygame.NOFRAME
done = False
fuchsia = (255, 0, 128)  # Transparency color
dark_red = (139, 0, 0)

# Set window transparency color
hwnd = pygame.display.get_wm_info()["window"]
win32gui.SetWindowLong(hwnd, win32con.GWL_EXSTYLE,
                       win32gui.GetWindowLong(hwnd, win32con.GWL_EXSTYLE) | win32con.WS_EX_LAYERED)
win32gui.SetLayeredWindowAttributes(hwnd, win32api.RGB(*fuchsia), 0, win32con.LWA_COLORKEY)

#Some controls
block=0
block1=0

#You can render some text
white=(255,255,255)
blue=(0,0,255)
font = pygame.font.Font('freesansbold.ttf', 32) 
texto=font.render('press "z" to define one corner and again to define the rectangle, it will take a screenshot', True, white, blue)
while not done:

    keys= pygame.key.get_pressed()
    pygame.time.delay(50)

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True

    #This controls the actions at starting and end point
    if block1==0:
        if keys[pygame.K_z]:
            if block==0:
                block=1
                n=win32gui.GetCursorPos()
            else:
                done=True
                break
            #this prevents double checks, can be handle also by using events
            block1=10

        else:
            m=win32gui.GetCursorPos()
    else:
        block1-=1        

    screen.fill(fuchsia)  # Transparent background
    #this will render some text
    screen.blit(texto,(0,0))
    #This will draw your rectangle
    if block==1:
        pygame.draw.line(screen,dark_red,(n[0],n[1]),(m[0],n[1]),1)
        pygame.draw.line(screen,dark_red,(n[0],m[1]),(m[0],m[1]),1)
        pygame.draw.line(screen,dark_red,(n[0],n[1]),(n[0],m[1]),1)
        pygame.draw.line(screen,dark_red,(m[0],n[1]),(m[0],m[1]),1)
        #    Drawing the independent lines is still a little faster than drawing a rectangle
        pygame.draw.rect(screen,dark_red,(min(n[0],m[0]),min(n[1],m[1]),abs(m[0]-n[0]),abs(m[1]-n[1])),1)
    pygame.display.update()    

pygame.display.quit()
pyautogui.screenshot(region=(min(n[0],m[0]),min(n[1],m[1]),abs(m[0]-n[0]),abs(m[1]-n[1])))

#draw either rectangles or circles by dragging the mouse like we do in Paint application

import cv2
import numpy as np

drawing = False # true if mouse is pressed
mode = True # if True, draw rectangle. Press 'm' to toggle to curve
ix,iy = -1,-1

#mouse callback function
def draw_circle(event,x,y,flags,param):
    global ix,iy,drawing,mode

    if event == cv2.EVENT_LBUTTONDOWN:
        drawing = True
        ix,iy = x,y

    elif event == cv2.EVENT_MOUSEMOVE:
        if drawing == True:
            if mode == True:
                cv2.rectangle(img,(ix,iy),(x,y),(0,255,0),-1)
            else:
                cv2.circle(img,(x,y),5,(0,0,255),-1)

    elif event == cv2.EVENT_LBUTTONUP:
        drawing = False
        if mode == True:
            cv2.rectangle(img,(ix,iy),(x,y),(0,255,0),-1)
        else:
            cv2.circle(img,(x,y),5,(0,0,255),-1)

#bind this mouse callback function to OpenCV window
img = np.zeros((512,512,3), np.uint8)
cv2.namedWindow('image')
cv2.setMouseCallback('image',draw_circle)

while(1):
    cv2.imshow('image',img)
    k = cv2.waitKey(1) & 0xFF
    if k == ord('m'):
        mode = not mode
    elif k == 27:
        break

cv2.destroyAllWindows()