Question

我正在尝试使用Selenium Web驱动程序和python从Google chrome中获取<canvas>标签元素的屏幕截图。

我尝试使用下面的代码

driver.find_element_by_css('#canvas-xyz').save_screenshot('canvas.png')

它回来了

AttributeError: 'WebElement' object has no attribute 'save_screenshot'

我也在开发工具中尝试过

document.querySelector('#canvas-xyz').toDataURL()

它返回了以下DATA URI，它为空。

data:image/png;base64,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

是否可以在python中使用chromedriver和selenium来获取元素的屏幕截图。我知道chrome开发工具允许我们截取特定元素的屏幕截图。即使是JavaScript方法，我也可以使用driver.execute_script()命令获取数据URI。

Answer 1

WebElement没有save_screenshot。您可以使用screenshot_as_png（属性）并将其保存

element = driver.find_element_by_css('#canvas-xyz')
scrrenshot = element.screenshot_as_png
with open('canvas.png', 'wb') as f:
    f.write(scrrenshot)

Answer 2

使用WebElement.screenshot()方法：

def screenshot(self, filename):
    """
    Saves a screenshot of the current element to a PNG image file. Returns
       False if there is any IOError, else returns True. Use full paths in
       your filename.

    :Args:
     - filename: The full path you wish to save your screenshot to. This
       should end with a `.png` extension.

    :Usage:
        element.screenshot('/Screenshots/foo.png')
    """

因此，在您的示例中，这将是：

driver.find_element_by_css('#canvas-xyz').screenshot('canvas.png')

硒元素截图-Google Chrome

2 个答案: