Selenium with C#

Browser Manipulation

https://www.selenium.dev/documentation/webdriver/

Browser Navigation

Navigate to

跳转到

driver.Navigate().GoToUrl(@"https://selenium.dev")

Back

后退

driver.Navigate().Back();

Forward

前进

driver.Navigate().Forward();

Refresh

刷新

driver.Navigate().Refresh();

Get Title

获取标题

driver.Title;

Windows and tabs

Get window handle

获取窗口句柄

driver.CurrentWindowHandle;

Switching windows

切换窗口

//Store the ID of the original window
string originalWindow = driver.CurrentWindowHandle;
​
//Check we don't have other windows open already
Assert.AreEqual(driver.WindowHandles.Count, 1);
​
//Click the link which opens in a new window
driver.FindElement(By.LinkText("new window")).Click();
​
//Wait for the new window or tab
wait.Until(wd => wd.WindowHandles.Count == 2);
​
//Loop through until we find a new window handle
foreach(string window in driver.WindowHandles)
{
    if(originalWindow != window)
    {
        driver.SwitchTo().Window(window);
        break;
    }
}
//Wait for the new tab to finish loading content
wait.Until(wd => wd.Title == "Selenium documentation");

Closing a window

关闭窗口

//Close the tab or window
driver.Close();
​
//Switch back to the old tab or window
driver.SwitchTo().Window(originalWindow);

Quitting the browser

退出浏览器

driver.Quit();

Window management

窗口管理

Get window size

获取窗口尺寸

//Access each dimension individually
int width = driver.Manage().Window.Size.Width;
int height = driver.Manage().Window.Size.Height;

//Or store the dimensions and query them later
System.Drawing.Size size = driver.Manage().Window.Size;
int width1 = size.Width;
int height1 = size.Height;
  

Set window size

设置窗口尺寸

driver.Manage().Window.Size = new Size(1024, 768);

Get window position

获取窗口位置

//Access each dimension individually
int x = driver.Manage().Window.Position.X;
int y = driver.Manage().Window.Position.Y;
​
//Or store the dimensions and query them later
Point position = driver.Manage().Window.Position;
int x1 = position.X;
int y1 = position.Y;

Set window position

设置窗口位置

// Move the window to the top left of the primary monitor
driver.Manage().Window.Position = new Point(0, 0);
  

Maximize/Minimize window

最大化/最小化窗口

driver.Manage().Window.Maximize();
driver.Manage().Window.Minimize();

Fullscreen window

全屏

driver.Manage().Window.FullScreen();

TakeScreenshot

截屏

  using OpenQA.Selenium;
  using OpenQA.Selenium.Chrome;
  using OpenQA.Selenium.Support.UI;
​
  var driver = new ChromeDriver();
  driver.Navigate().GoToUrl("http://www.example.com");
  Screenshot screenshot = (driver as ITakesScreenshot).GetScreenshot();
  screenshot.SaveAsFile("screenshot.png", ScreenshotImageFormat.Png); // Format values are Bmp, Gif, Jpeg, Png, Tiff
  

TakeElementScreenshot

元素截屏

    using OpenQA.Selenium;
    using OpenQA.Selenium.Chrome;
    using OpenQA.Selenium.Support.UI;
​
    // Webdriver
    var driver = new ChromeDriver();
    driver.Navigate().GoToUrl("http://www.example.com");
​
    // Fetch element using FindElement
    var webElement = driver.FindElement(By.CssSelector("h1"));
​
    // Screenshot for the element
    var elementScreenshot = (webElement as ITakesScreenshot).GetScreenshot();
    elementScreenshot.SaveAsFile("screenshot_of_element.png");
  

Execute Script

执行Javascript语句

    //creating Chromedriver instance
    IWebDriver driver = new ChromeDriver();
    //Creating the JavascriptExecutor interface object by Type casting
    IJavaScriptExecutor js = (IJavaScriptExecutor) driver;
    //Button Element
    IWebElement button = driver.FindElement(By.Name("btnLogin"));
    //Executing JavaScript to click on element
    js.ExecuteScript("arguments[0].click();", button);
    //Get return value from script
    String text = (String)js.ExecuteScript("return arguments[0].innerText", button);
    //Executing JavaScript directly
    js.ExecuteScript("console.log('hello world')");
  

Locating elements

 

Locating one element

定位元素

使用 WebDriver 时要学习的最基本技术之一是如何在页面上查找元素。WebDriver 提供了许多内置的选择器类型，其中通过 ID 属性查找元素：

IWebElement element = driver.FindElement(By.Id("cheese"));

如示例所示，在 WebDriver 中定位元素是在WebDriver实例对象上完成的 。该findElement(By)方法返回另一个基本对象类型，WebElement.

• WebDriver 代表浏览器

• WebElement 表示特定的 DOM 节点（控件，例如链接或输入字段等）

递进查找

IWebElement cheese = driver.FindElement(By.Id("cheese"));
IWebElement cheddar = cheese.FindElement(By.Id("cheddar"));
//CssSelector定位
driver.FindElement(By.CssSelector("#cheese #cheddar"));

查找元素集合

IReadOnlyList<IWebElement> muchoCheese = driver.FindElements(By.CssSelector("#cheese li"));

Element selection strategies

元素选择策略

Locator	Description
class name	Locates elements whose class name contains the search value (compound class names are not permitted)
css selector	Locates elements matching a CSS selector
id	Locates elements whose ID attribute matches the search value
name	Locates elements whose NAME attribute matches the search value
link text	Locates anchor elements whose visible text matches the search value
partial link text	Locates anchor elements whose visible text contains the search value. If multiple elements are matching, only the first one will be selected.
tag name	Locates elements whose tag name matches the search value
xpath	Locates elements matching an XPath expression

使用选择器的技巧

通常，如果 HTML ID 可用、唯一且一致可预测，则它们是在页面上定位元素的首选方法。它们往往工作得非常快，并且放弃了复杂的 DOM 遍历带来的大量处理。

如果唯一 ID 不可用，则编写良好的 CSS 选择器是定位元素的首选方法。XPath 与 CSS 选择器一样有效，但语法复杂且经常难以调试。尽管 XPath 选择器非常灵活，但它们通常没有经过浏览器供应商的性能测试，而且往往很慢。

基于linkText和partialLinkText 的选择策略的缺点在于它们仅适用于链接元素。此外，它们在 WebDriver 内部调用 XPath 选择器。

标签名称可能是一种危险的定位元素的方式。页面上经常会出现多个相同标签的元素。这在调用返回元素集合的findElements(By)方法时非常有用。

建议是使您的定位器尽可能紧凑和可读。要求 WebDriver 遍历 DOM 结构是一项代价高昂的操作，您可以缩小搜索范围越多越好。

相对定位器

Selenium 4 特性

using static OpenQA.Selenium.RelativeBy;
​
IWebElement passwordField = driver.FindElement(By.Id("password"));
IWebElement emailAddressField = driver.FindElement(WithTagName("input").Above(passwordField));
  

using static OpenQA.Selenium.RelativeBy;
​
IWebElement submitButton = driver.FindElement(By.Id("submit"));
IWebElement cancelButton = driver.FindElement(WithTagName("button").LeftOf(submitButton));
  

using static OpenQA.Selenium.RelativeBy;
​
IWebElement emailAddressLabel = driver.FindElement(By.Id("lbl-email"));
IWebElement emailAddressField = driver.FindElement(WithTagName("input").Near(emailAddressLabel));

Waits

Explicit wait

显示等待

driver = new ChromeDriver();
driver.Url = "https://www.google.com/ncr";
driver.FindElement(By.Name("q")).SendKeys("cheese" + Keys.Enter);
            
WebDriverWait wait = new WebDriverWait(driver, TimeSpan.FromSeconds(10));
IWebElement firstResult = wait.Until(e => e.FindElement(By.XPath("//a/h3")));
​
Console.WriteLine(firstResult.Text);

匿名函数优化

   using (var driver = new FirefoxDriver())
    {
        var foo = new WebDriverWait(driver, TimeSpan.FromSeconds(3))
                        .Until(drv => drv.FindElement(By.Name("q")));
        Debug.Assert(foo.Text.Equals("Hello from JavaScript!"));
    }

预期条件

元素可点击

new WebDriverWait(driver, TimeSpan.FromSeconds(3)).Until(ExpectedConditions.ElementToBeClickable(By.XPath("//a/h3")));

Implicit wait

隐式等待

通过隐式等待，WebDriver 在尝试查找任何元素时会在一段时间内轮询 DOM 。

警告： 不要混合隐式和显式等待。这样做可能会导致不可预测的等待时间。

IWebDriver driver = new ChromeDriver();
driver.Manage().Timeouts().ImplicitWait = TimeSpan.FromSeconds(10);
driver.Url = "http://somedomain/url_that_delays_loading";
IWebElement dynamicElement = driver.FindElement(By.Name("dynamicElement"));
  

FluentWait

流利等待

FluentWait 实例定义了等待条件的最长时间，以及检查条件的频率

用户可以将等待配置为在等待时忽略特定类型的异常，例如NoSuchElementException在页面上搜索元素时。

using (var driver = new FirefoxDriver())
{
  WebDriverWait wait = new WebDriverWait(driver, timeout: TimeSpan.FromSeconds(30))
  {
      PollingInterval = TimeSpan.FromSeconds(5),
  };
  wait.IgnoreExceptionTypes(typeof(NoSuchElementException));
​
  var foo = wait.Until(drv => drv.FindElement(By.Id("foo")));
}

JavaScript alerts, prompts and confirmations

Alerts

//Click the link to activate the alert
driver.FindElement(By.LinkText("See an example alert")).Click();
​
//Wait for the alert to be displayed and store it in a variable
IAlert alert = wait.Until(ExpectedConditions.AlertIsPresent());
​
//Store the alert text in a variable
string text = alert.Text;
​
//Press the OK button
alert.Accept();
  

Confirm

//Click the link to activate the alert
driver.FindElement(By.LinkText("See a sample confirm")).Click();
​
//Wait for the alert to be displayed
wait.Until(ExpectedConditions.AlertIsPresent());
​
//Store the alert in a variable
IAlert alert = driver.SwitchTo().Alert();
​
//Store the alert in a variable for reuse
string text = alert.Text;
​
//Press the Cancel button
alert.Dismiss();

Prompt

提示

//Click the link to activate the alert
driver.FindElement(By.LinkText("See a sample prompt")).Click();
​
//Wait for the alert to be displayed and store it in a variable
IAlert alert = wait.Until(ExpectedConditions.AlertIsPresent());
​
//Type your message
alert.SendKeys("Selenium");
​
//Press the OK button
alert.Accept();
  

Http proxies

代理服务器充当客户端和服务器之间请求的中介。简而言之，流量通过代理服务器流向您请求的地址并返回。

带有 Selenium 的自动化脚本代理服务器可能有助于：

• 捕获网络流量

• 模拟网站进行的后端调用

• 在复杂的网络拓扑或严格的公司限制/政策下访问所需的网站。

using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
​
public class ProxyTest{
  public static void Main() {
    ChromeOptions options = new ChromeOptions();
    Proxy proxy = new Proxy();
    proxy.Kind = ProxyKind.Manual;
    proxy.IsAutoDetect = false;
    proxy.SslProxy = "<HOST:PORT>";
    options.Proxy = proxy;
    options.AddArgument("ignore-certificate-errors");
    IWebDriver driver = new ChromeDriver(options);
    driver.Navigate().GoToUrl("https://www.selenium.dev/");
  }
}

Page loading strategy

normal

using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
​
namespace pageLoadStrategy {
  class pageLoadStrategy {
    public static void Main(string[] args) {
      var chromeOptions = new ChromeOptions();
      chromeOptions.PageLoadStrategy = PageLoadStrategy.Normal;
      IWebDriver driver = new ChromeDriver(chromeOptions);
      try {
        driver.Navigate().GoToUrl("https://example.com");
      } finally {
        driver.Quit();
      }
    }
  }
}
  

eager

using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
​
namespace pageLoadStrategy {
  class pageLoadStrategy {
    public static void Main(string[] args) {
      var chromeOptions = new ChromeOptions();
      chromeOptions.PageLoadStrategy = PageLoadStrategy.Eager;
      IWebDriver driver = new ChromeDriver(chromeOptions);
      try {
        driver.Navigate().GoToUrl("https://example.com");
      } finally {
        driver.Quit();
      }
    }
  }
}

none

using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;
​
namespace pageLoadStrategy {
  class pageLoadStrategy {
    public static void Main(string[] args) {
      var chromeOptions = new ChromeOptions();
      chromeOptions.PageLoadStrategy = PageLoadStrategy.None;
      IWebDriver driver = new ChromeDriver(chromeOptions);
      try {
        driver.Navigate().GoToUrl("https://example.com");
      } finally {
        driver.Quit();
      }
    }
  }
}

Web element

Find Element

// Get search box element from webElement 'q' using Find Element
IWebElement searchbox = driver.FindElement(By.Name("q"));

Find Elements

using OpenQA.Selenium;
using OpenQA.Selenium.Firefox;
using System.Collections.Generic;
​
namespace FindElementsExample {
 class FindElementsExample {
  public static void Main(string[] args) {
   IWebDriver driver = new FirefoxDriver();
   try {
    // Navigate to Url
    driver.Navigate().GoToUrl("https://example.com");
​
    // Get all the elements available with tag name 'p'
    IList < IWebElement > elements = driver.FindElements(By.TagName("p"));
    foreach(IWebElement e in elements) {
     System.Console.WriteLine(e.Text);
    }
​
   } finally {
    driver.Quit();
   }
  }
 }
}

Find Element From Element

IWebElement searchForm = driver.FindElement(By.TagName("form"));
IWebElement searchbox = searchForm.FindElement(By.Name("q"));

Find Elements From Element

  // Get element with tag name 'div'
    IWebElement element = driver.FindElement(By.TagName("div"));
​
    // Get all the elements available with tag name 'p'
    IList < IWebElement > elements = element.FindElements(By.TagName("p"));
    foreach(IWebElement e in elements) {
     System.Console.WriteLine(e.Text);
    }

Get Active Element

它用于跟踪（或）查找在当前浏览上下文中具有焦点的 DOM 元素。

    using OpenQA.Selenium;
    using OpenQA.Selenium.Chrome;
​
    namespace ActiveElement {
     class ActiveElement {
      public static void Main(string[] args) {
       IWebDriver driver = new ChromeDriver();
       try {
        // Navigate to Url
        driver.Navigate().GoToUrl("https://www.google.com");
        driver.FindElement(By.CssSelector("[name='q']")).SendKeys("webElement");
​
        // Get attribute of current active element
        string attr = driver.SwitchTo().ActiveElement().GetAttribute("title");
        System.Console.WriteLine(attr);
       } finally {
        driver.Quit();
       }
      }
     }
    }

Is Element Enabled

// Store the WebElement
IWebElement element = driver.FindElement(By.Name("btnK"));
​
// Prints true if element is enabled else returns false
System.Console.WriteLine(element.Enabled);
  

Get Element Rect

获取元素矩形

driver.Navigate().GoToUrl("https://example.com");
​
var res = driver.FindElement(By.CssSelector("h1"));
// Return x and y coordinates referenced element
System.Console.WriteLine(res.Location);
// Returns height, width
System.Console.WriteLine(res.Size);

Get Element CSS Value

获取元素 CSS 值

// Navigate to Url
driver.Navigate().GoToUrl("https://www.example.com");
​
// Retrieves the computed style property 'color' of linktext
String cssValue = driver.FindElement(By.LinkText("More information...")).GetCssValue("color");

Get Element Text

// Navigate to url
driver.Url="https://example.com";
​
// Retrieves the text of the element
String text = driver.FindElement(By.CssSelector("h1")).Text;

Keyboard

键盘代表一个键盘事件。KeyBoard 操作是通过使用低级接口执行的，这允许我们向 Web 浏览器提供虚拟化设备输入。

sendKeys

  // Enter "webdriver" text and perform "ENTER" keyboard action
  driver.FindElement(By.Name("q")).SendKeys("webdriver" + Keys.Enter);

keyDown

keyDown 用于模拟按下修饰键（CONTROL、SHIFT、ALT）的动作

  // Perform action ctrl + A (modifier CONTROL + Alphabet A) to select the page
  Actions actionProvider = new Actions(driver);
  IAction keydown = actionProvider.KeyDown(Keys.Control).SendKeys("a").Build();
  keydown.Perform();

keyUp

keyUp 用于模拟修饰键（CONTROL、SHIFT、ALT）的上键（或）键释放动作

// Enters text "qwerty" with keyDown SHIFT key and after keyUp SHIFT key (QWERTYqwerty)
        action.KeyDown(Keys.Shift).SendKeys(search, "qwerty").KeyUp(Keys.Shift).SendKeys("qwerty").Perform();