OpenQA.Selenium.NoSuchElementException: Unable to locate element error while locating an element on a page using Selenium and C#

问题

I am trying to scrape the text 睡觉 within the page edited out the site

It has the css selector:

#autocplt_wrap > ul:nth-child(1) > li:nth-child(1) > span:nth-child(1) > a:nth-child(1)

And x-Path:

/html/body/div[2]/div[1]/div[3]/div[2]/div[1]/div/div[1]/div[2]/div/div/ul[1]/li/span/a[1]

My code is:

IWebDriver driver = new FirefoxDriver();
WebDriverWait wait = new WebDriverWait(driver, TimeSpan.FromSeconds(10));
//load webdriver
driver.Manage();
driver.Navigate().GoToUrl("https://dict.naver.com/linedict/zhendict/#/cnen/home");
driver.FindElement(By.ClassName("ac_input")).SendKeys("睡觉" + Keys.Enter);
driver.FindElement(By.CssSelector("#autocplt_wrap > ul:nth-child(1) > li:nth-child(1) > span:nth-child(1) > a:nth-child(1)"));

No matter what I try I always get the error:

Unhandled exception. OpenQA.Selenium.NoSuchElementException: Unable to locate element: #autocplt_wrap > ul:nth-child(1) > 
li:nth-child(1) > span:nth-child(1) > a:nth-child(1)
   at OpenQA.Selenium.Remote.RemoteWebDriver.UnpackAndThrowOnError(Response errorResponse)
   at OpenQA.Selenium.Remote.RemoteWebDriver.Execute(String driverCommandToExecute, Dictionary`2 parameters)
   at OpenQA.Selenium.Remote.RemoteWebDriver.FindElement(String mechanism, String value)
   at OpenQA.Selenium.By.<>c__DisplayClass29_0.<CssSelector>b__0(ISearchContext context)
   at OpenQA.Selenium.By.FindElement(ISearchContext context)
   at OpenQA.Selenium.Remote.RemoteWebDriver.FindElement(By by)

回答1:

The desired element is a dynamic element so to extract the text 睡觉 you have to induce WebDriverWait for the desired ElementIsVisible() and you can use either of the following Locator Strategies:

CssSelector:

Console.WriteLine(new WebDriverWait(driver, TimeSpan.FromSeconds(20)).Until(ExpectedConditions.ElementIsVisible(By.CssSelector("a.srchword[data-entryid]"))).GetAttribute("innerHTML"));

XPath:

Console.WriteLine(new WebDriverWait(driver, TimeSpan.FromSeconds(20)).Until(ExpectedConditions.ElementIsVisible(By.XPath("//a[@class='srchword' and @data-entryid]"))).GetAttribute("innerHTML"));

Using `DotNetSeleniumExtras.WaitHelpers` with `nuget`

CssSelector:

Console.WriteLine(new WebDriverWait(driver, TimeSpan.FromSeconds(10)).Until(SeleniumExtras.WaitHelpers.ExpectedConditions.ElementIsVisible(By.CssSelector("a.srchword[data-entryid]"))).GetAttribute("innerHTML"));

XPath:

Console.WriteLine(new WebDriverWait(driver, TimeSpan.FromSeconds(10)).Until(SeleniumExtras.WaitHelpers.ExpectedConditions.ElementIsVisible(By.XPath("//a[@class='srchword' and @data-entryid]"))).GetAttribute("innerHTML"));