Selenium WebDriver C#完整网站截图使用ChromeDriver和FirefoxDriver

Question

当我使用ChromeDriver截取屏幕截图时,我会获得具有视口大小的屏幕.
当我使用FirefoxDriver截取屏幕截图时,我得到了我想要的内容,这是一个网站的全屏幕打印.

ChromeDriver声明如下:

IWebDriver driver = new ChromeDriver();

FirefoxDriver声明如下:

IWebDriver driver = new FirefoxDriver();

两个驱动程序执行相同的代

driver.Manage().Window.Maximize();
driver.Navigate().GoToUrl(url);//url is a string variable
ITakesScreenshot screenshotDriver = driver as ITakesScreenshot;
Screenshot screenshot = screenshotDriver.GetScreenshot();
screenshot.SaveAsFile("c:/test.png", ImageFormat.Png);

ChromeDriver的test.png分辨率为1920x1099,仅包含浏览器视口.
FirefoxDriver的test.png分辨率为1903x16559,包含整个页面.

我知道该GetScreenshot()方法不会返回相同的分辨率大小,因为它在IEDriver,FirefoxDriver,OperaDriver,ChromeDriver中的实现略有不同.

我的问题是:

1. 为什么ChromeDriver和FirefoxDriver的.GetScreenshot()方法之间存在这样的差异,即使他们使用相同的界面(ITakesScreenshot)？

2. 有没有办法让ChromeDriver的GetScreenshot()方法返回整个网页屏幕而不仅仅是视口？

Answer 1

我们无法使用ChromeDriver2获取整个页面截图,我们需要进行手动实现.我已经修改了一个方法,可以在博客中使用ChromeDriver工作正常.

使用此方法如下:

private IWebDriver _driver = new ChromeDriver(CHROME_DRIVER_PATH);
screenshot.SaveAsFile(saveFileName, ImageFormat.Jpeg);

public Bitmap GetEntereScreenshot()
    {

        Bitmap stitchedImage = null;
        try
        {
            long totalwidth1 = (long)((IJavaScriptExecutor)_driver).ExecuteScript("return document.body.offsetWidth");//documentElement.scrollWidth");

            long totalHeight1 = (long)((IJavaScriptExecutor)_driver).ExecuteScript("return  document.body.parentNode.scrollHeight");

            int totalWidth = (int)totalwidth1;
            int totalHeight = (int)totalHeight1;

            // Get the Size of the Viewport
            long viewportWidth1 = (long)((IJavaScriptExecutor)_driver).ExecuteScript("return document.body.clientWidth");//documentElement.scrollWidth");
            long viewportHeight1 = (long)((IJavaScriptExecutor)_driver).ExecuteScript("return window.innerHeight");//documentElement.scrollWidth");

            int viewportWidth = (int)viewportWidth1;
            int viewportHeight = (int)viewportHeight1;


        // Split the Screen in multiple Rectangles
        List<Rectangle> rectangles = new List<Rectangle>();
        // Loop until the Total Height is reached
        for (int i = 0; i < totalHeight; i += viewportHeight)
        {
            int newHeight = viewportHeight;
            // Fix if the Height of the Element is too big
            if (i + viewportHeight > totalHeight)
            {
                newHeight = totalHeight - i;
            }
            // Loop until the Total Width is reached
            for (int ii = 0; ii < totalWidth; ii += viewportWidth)
            {
                int newWidth = viewportWidth;
                // Fix if the Width of the Element is too big
                if (ii + viewportWidth > totalWidth)
                {
                    newWidth = totalWidth - ii;
                }

                // Create and add the Rectangle
                Rectangle currRect = new Rectangle(ii, i, newWidth, newHeight);
                rectangles.Add(currRect);
            }
        }

        // Build the Image
        stitchedImage = new Bitmap(totalWidth, totalHeight);
        // Get all Screenshots and stitch them together
        Rectangle previous = Rectangle.Empty;
        foreach (var rectangle in rectangles)
        {
            // Calculate the Scrolling (if needed)
            if (previous != Rectangle.Empty)
            {
                int xDiff = rectangle.Right - previous.Right;
                int yDiff = rectangle.Bottom - previous.Bottom;
                // Scroll
                //selenium.RunScript(String.Format("window.scrollBy({0}, {1})", xDiff, yDiff));
                ((IJavaScriptExecutor)_driver).ExecuteScript(String.Format("window.scrollBy({0}, {1})", xDiff, yDiff));
                System.Threading.Thread.Sleep(200);
            }

            // Take Screenshot
            var screenshot = ((ITakesScreenshot)_driver).GetScreenshot();

            // Build an Image out of the Screenshot
            Image screenshotImage;
            using (MemoryStream memStream = new MemoryStream(screenshot.AsByteArray))
            {
                screenshotImage = Image.FromStream(memStream);
            }

            // Calculate the Source Rectangle
            Rectangle sourceRectangle = new Rectangle(viewportWidth - rectangle.Width, viewportHeight - rectangle.Height, rectangle.Width, rectangle.Height);

            // Copy the Image
            using (Graphics g = Graphics.FromImage(stitchedImage))
            {
                g.DrawImage(screenshotImage, rectangle, sourceRectangle, GraphicsUnit.Pixel);
            }

            // Set the Previous Rectangle
            previous = rectangle;
        }
        }
        catch (Exception ex)
        {
            // handle
        }
        return stitchedImage;
    }

Answer 2

我清理了@Selvantharajah Roshanth的答案,并添加了一个检查,以便它不会尝试将已经适合视口的屏幕截图拼接在一起.

public Image GetEntireScreenshot()
{
    // Get the total size of the page
    var totalWidth = (int) (long) ((IJavaScriptExecutor) driver).ExecuteScript("return document.body.offsetWidth"); //documentElement.scrollWidth");
    var totalHeight = (int) (long) ((IJavaScriptExecutor) driver).ExecuteScript("return  document.body.parentNode.scrollHeight");
    // Get the size of the viewport
    var viewportWidth = (int) (long) ((IJavaScriptExecutor) driver).ExecuteScript("return document.body.clientWidth"); //documentElement.scrollWidth");
    var viewportHeight = (int) (long) ((IJavaScriptExecutor) driver).ExecuteScript("return window.innerHeight"); //documentElement.scrollWidth");

    // We only care about taking multiple images together if it doesn't already fit
    if (totalWidth <= viewportWidth && totalHeight <= viewportHeight)
    {
        var screenshot = driver.TakeScreenshot();
        return ScreenshotToImage(screenshot);
    }
    // Split the screen in multiple Rectangles
    var rectangles = new List<Rectangle>();
    // Loop until the totalHeight is reached
    for (var y = 0; y < totalHeight; y += viewportHeight)
    {
        var newHeight = viewportHeight;
        // Fix if the height of the element is too big
        if (y + viewportHeight > totalHeight)
        {
            newHeight = totalHeight - y;
        }
        // Loop until the totalWidth is reached
        for (var x = 0; x < totalWidth; x += viewportWidth)
        {
            var newWidth = viewportWidth;
            // Fix if the Width of the Element is too big
            if (x + viewportWidth > totalWidth)
            {
                newWidth = totalWidth - x;
            }
            // Create and add the Rectangle
            var currRect = new Rectangle(x, y, newWidth, newHeight);
            rectangles.Add(currRect);
        }
    }
    // Build the Image
    var stitchedImage = new Bitmap(totalWidth, totalHeight);
    // Get all Screenshots and stitch them together
    var previous = Rectangle.Empty;
    foreach (var rectangle in rectangles)
    {
        // Calculate the scrolling (if needed)
        if (previous != Rectangle.Empty)
        {
            var xDiff = rectangle.Right - previous.Right;
            var yDiff = rectangle.Bottom - previous.Bottom;
            // Scroll
            ((IJavaScriptExecutor) driver).ExecuteScript(String.Format("window.scrollBy({0}, {1})", xDiff, yDiff));
        }
        // Take Screenshot
        var screenshot = driver.TakeScreenshot();
        // Build an Image out of the Screenshot
        var screenshotImage = ScreenshotToImage(screenshot);
        // Calculate the source Rectangle
        var sourceRectangle = new Rectangle(viewportWidth - rectangle.Width, viewportHeight - rectangle.Height, rectangle.Width, rectangle.Height);
        // Copy the Image
        using (var graphics = Graphics.FromImage(stitchedImage))
        {
            graphics.DrawImage(screenshotImage, rectangle, sourceRectangle, GraphicsUnit.Pixel);
        }
        // Set the Previous Rectangle
        previous = rectangle;
    }
    return stitchedImage;
}

private static Image ScreenshotToImage(Screenshot screenshot)
{
    Image screenshotImage;
    using (var memStream = new MemoryStream(screenshot.AsByteArray))
    {
        screenshotImage = Image.FromStream(memStream);
    }
    return screenshotImage;
}

Answer 3

由于之前的实现存在一些不准确之处，ChromeDriver 似乎尚未实现全屏屏幕截图。

来源： https: //code.google.com/p/chromedriver/issues/detail? id=294

我最近编写了一个基于 Selenium 的应用程序来测试 Internet Explorer UI，发现：

1. 使用 selenium 进行屏幕截图并不像使用 .NET 那样快，而且
2. 当出现对话框时，Selenium 无法截取屏幕截图。这是一个主要缺点，因为我需要在与页面交互期间识别意外的对话框。

研究使用 System.Drawing 中的 Graphics.CopyFromScreen 方法作为替代解决方案，直到该功能在 Chrome 中实现。然而，一旦您尝试过 .the Net 方法，我认为您不会回头 =]