selenium无法截取网页元素

Question

我可以使用Firefox.get_screenshot_as_file（＆＃39; 2.png＆＃39;）截取整个页面，但是当我使用passage.screenshot（＆＃39; 1.png＆＃39;）截取网页元素时，它总是提出这个例外：

selenium.common.exceptions.WebDriverException: Message: Unrecognized command: GET /session/284283fa-53fc-4b33-b329-e6e888dbdcb0/screenshot/{35834cf1-c9c7-4129-99b1-24f30c6b56e6}

Answer 1

您收到此异常是因为如果没有某些第三方库或您自己的代码来处理此问题，您无法在selenium中截取元素。见This stackoverflow post

使用名为PIL的库来执行此操作：

from selenium import webdriver
from PIL import Image

fox = webdriver.Firefox()
fox.get('https://stackoverflow.com/')

# now that we have the preliminary stuff out of the way time to get that image :D
element = fox.find_element_by_id('hlogo') # find part of the page you want image of
location = element.location
size = element.size
fox.save_screenshot('screenshot.png') # saves screenshot of entire page
fox.quit()

im = Image.open('screenshot.png') # uses PIL library to open image in memory

left = location['x']
top = location['y']
right = location['x'] + size['width']
bottom = location['y'] + size['height']


im = im.crop((left, top, right, bottom)) # defines crop points
im.save('screenshot.png') # saves new cropped image

Answer 2

Firefox驱动程序中未实现Web元素的屏幕截图。解决方法是从屏幕截图中裁剪目标元素：

import StringIO
from selenium import webdriver
from PIL import Image

driver = webdriver.Firefox()
driver.get('http://stackoverflow.com')

# get the logo element
element = driver.find_element_by_id('hlogo')

# crop to the logo from the screenshot
rect = element.rect
points = [rect['x'], rect['y'], rect['x'] + rect['width'], rect['y'] + rect['height']]
with Image.open(StringIO.StringIO(driver.get_screenshot_as_png())) as img :
    with img.crop(points) as imgsub :
        imgsub.save("c:\\temp\\logo.png", 'PNG')