python - 如何在Python中的给定窗口中捕获鼠标移动？

Question

我知道如何捕获整个屏幕的鼠标移动，但是我想捕获python中特定窗口中的鼠标移动。我需要在该特定窗口中跟踪鼠标的位置。

Answer 1

您需要创建一个窗口。

cv2.namedWindow(winname='my_drawing', flags=cv2.WINDOW_NORMAL)

可选:如果需要，可以调整窗口大小:

cv2.resizeWindow(winname='my_drawing', width=600, height=600)

您需要一个鼠标callback函数，该函数将返回鼠标坐标。假设我要在屏幕上绘制矩形。

cv2.setMouseCallback('my_drawing', draw_rectangle)

我的draw_rectangle将为:

def draw_rectangle(event, x, y, flags, param):
    global x_mouse, y_mouse
    if event == cv2.EVENT_LBUTTONDOWN:
        cv2.rectangle(img, pt1=(x, y), 
                      pt2=(x+10, y+10), 
                      color=(180, 105, 255),
                      thickness=4)
    cv2.imshow('my_drawing', img)
    cv2.waitKey(0)
    x_mouse, y_mouse = x, y

我们有两个global变量，我们将在函数外部声明为

x_mouse, y_mouse = (None, None)

因为我打算在图像上绘制一个矩形。我应该声明与名为window的my_drawing相同大小的RGB图像。

img = np.zeros((600, 600, 3), np.uint8)

下面的部分是可选的，我想在按s关键字时显示坐标。

while True:
    cv2.imshow('my_drawing', img)
    k = cv2.waitKey(0) & 0xFF
    if k == 27:
        break
    elif k == ord('s'):
        print("x, y = ({}, {})".format(x_mouse, y_mouse))

因此，当我在屏幕上单击一次并在 s关键字上单击2次时，结果将是:

x, y = (503, 420)
x, y = (363, 362)
x, y = (499, 274)
x, y = (289, 291)
x, y = (304, 439)

码:

import cv2
import numpy as np

x_mouse, y_mouse = (None, None)


def draw_rectangle(event, x, y, flags, param):
    global x_mouse, y_mouse
    if event == cv2.EVENT_LBUTTONDOWN:
        cv2.rectangle(img, pt1=(x, y),
                      pt2=(x+10, y+10),
                      color=(180, 105, 255),
                      thickness=4)
        cv2.imshow('my_drawing', img)
        cv2.waitKey(0)
        x_mouse, y_mouse = x, y


cv2.namedWindow(winname='my_drawing', flags=cv2.WINDOW_NORMAL)
cv2.resizeWindow(winname='my_drawing', width=600, height=600)
cv2.setMouseCallback('my_drawing', draw_rectangle)
img = np.zeros((600, 600, 3), np.uint8)
while True:
    cv2.imshow('my_drawing', img)
    k = cv2.waitKey(10) & 0xFF
    if k == 27:
        break
    elif k == ord('s'):
        print("x, y = ({}, {})".format(x_mouse, y_mouse))
cv2.destroyAllWindows()