我想确保在webdriver开始执行操作之前存在一个元素。
我正试图让这样的东西起作用：
WebDriverWait wait = new WebDriverWait(driver, new TimeSpan(0,0,5));
wait.Until(By.Id("login"));
我主要是在努力设置匿名函数。
或者，您可以使用隐式等待：
driver.Manage().Timeouts().ImplicitWait = TimeSpan.FromSeconds(10);
隐式等待是指在尝试查找一个或多个元素（如果它们不是立即可用）时，WebDriver轮询DOM一段时间。默认设置为0.设置后，将为WebDriver对象实例的生命周期设置隐式等待。
//wait up to 5 seconds with no minimum for a UI element to be found
WebDriverWait wait = new WebDriverWait(_pagedriver, TimeSpan.FromSeconds(5));
IWebElement title = wait.Until<IWebElement>((d) =>
{
return d.FindElement(By.ClassName("MainContentHeader"));
});
试试这段代码：
New WebDriverWait(driver, TimeSpan.FromSeconds(10)).Until(Function(d) d.FindElement(By.Id("controlName")).Displayed)
明确等待
public static WebDriverWait wait = new WebDriverWait(driver, 60);
例：
wait.until(ExpectedConditions.visibilityOfElementLocated(UiprofileCre.UiaddChangeUserLink));
public bool doesWebElementExist(string linkexist)
{
try
{
driver.FindElement(By.XPath(linkexist));
return true;
}
catch (NoSuchElementException e)
{
return false;
}
}
您不希望在元素更改之前等待太久。在此代码中，webdriver在继续之前等待最多2秒。
WebDriverWait wait = new WebDriverWait(driver, TimeSpan.FromMilliseconds(2000));
wait.Until(ExpectedConditions.VisibilityOfAllElementsLocatedBy(By.Name("html-name")));
由于我正在使用已经找到的IWebElement分隔页面元素定义和页面测试场景，因此可以像这样进行：
public static void WaitForElementToBecomeVisibleWithinTimeout(IWebDriver driver, IWebElement element, int timeout)
{
new WebDriverWait(driver, TimeSpan.FromSeconds(timeout)).Until(ElementIsVisible(element));
}
private static Func<IWebDriver, bool> ElementIsVisible(IWebElement element)
{
return driver => {
try
{
return element.Displayed;
}
catch(Exception)
{
// If element is null, stale or if it cannot be located
return false;
}
};
}
我看到已发布的多个解决方案非常有用！但是，如果有人需要别的东西，我想我会发布两个我个人在selenium C＃中使用的解决方案来测试一个元素是否存在！希望它有所帮助，欢呼！
public static class IsPresent
{
public static bool isPresent(this IWebDriver driver, By bylocator)
{
bool variable = false;
try
{
IWebElement element = driver.FindElement(bylocator);
variable = element != null;
}
catch (NoSuchElementException){
}
return variable;
}
}
这是第二个
public static class IsPresent2
{
public static bool isPresent2(this IWebDriver driver, By bylocator)
{
bool variable = true;
try
{
IWebElement element = driver.FindElement(bylocator);
}
catch (NoSuchElementException)
{
variable = false;
}
return variable;
}
}
使用Rn222和Aknuds1来使用返回单个元素或列表的ISearchContext。并且可以指定最少数量的元素：
public static class SearchContextExtensions
{
/// <summary>
/// Method that finds an element based on the search parameters within a specified timeout.
/// </summary>
/// <param name="context">The context where this is searched. Required for extension methods</param>
/// <param name="by">The search parameters that are used to identify the element</param>
/// <param name="timeOutInSeconds">The time that the tool should wait before throwing an exception</param>
/// <returns> The first element found that matches the condition specified</returns>
public static IWebElement FindElement(this ISearchContext context, By by, uint timeOutInSeconds)
{
if (timeOutInSeconds > 0)
{
var wait = new DefaultWait<ISearchContext>(context);
wait.Timeout = TimeSpan.FromSeconds(timeOutInSeconds);
return wait.Until<IWebElement>(ctx => ctx.FindElement(by));
}
return context.FindElement(by);
}
/// <summary>
/// Method that finds a list of elements based on the search parameters within a specified timeout.
/// </summary>
/// <param name="context">The context where this is searched. Required for extension methods</param>
/// <param name="by">The search parameters that are used to identify the element</param>
/// <param name="timeoutInSeconds">The time that the tool should wait before throwing an exception</param>
/// <returns>A list of all the web elements that match the condition specified</returns>
public static IReadOnlyCollection<IWebElement> FindElements(this ISearchContext context, By by, uint timeoutInSeconds)
{
if (timeoutInSeconds > 0)
{
var wait = new DefaultWait<ISearchContext>(context);
wait.Timeout = TimeSpan.FromSeconds(timeoutInSeconds);
return wait.Until<IReadOnlyCollection<IWebElement>>(ctx => ctx.FindElements(by));
}
return context.FindElements(by);
}
/// <summary>
/// Method that finds a list of elements with the minimum amount specified based on the search parameters within a specified timeout.<br/>
/// </summary>
/// <param name="context">The context where this is searched. Required for extension methods</param>
/// <param name="by">The search parameters that are used to identify the element</param>
/// <param name="timeoutInSeconds">The time that the tool should wait before throwing an exception</param>
/// <param name="minNumberOfElements">
/// The minimum number of elements that should meet the criteria before returning the list <para/>
/// If this number is not met, an exception will be thrown and no elements will be returned
/// even if some did meet the criteria
/// </param>
/// <returns>A list of all the web elements that match the condition specified</returns>
public static IReadOnlyCollection<IWebElement> FindElements(this ISearchContext context, By by, uint timeoutInSeconds, int minNumberOfElements)
{
var wait = new DefaultWait<ISearchContext>(context);
if (timeoutInSeconds > 0)
{
wait.Timeout = TimeSpan.FromSeconds(timeoutInSeconds);
}
// Wait until the current context found the minimum number of elements. If not found after timeout, an exception is thrown
wait.Until<bool>(ctx => ctx.FindElements(by).Count >= minNumberOfElements);
//If the elements were successfuly found, just return the list
return context.FindElements(by);
}
}
用法示例：
var driver = new FirefoxDriver();
driver.Navigate().GoToUrl("http://localhost");
var main = driver.FindElement(By.Id("main"));
// It can be now used to wait when using elements to search
var btn = main.FindElement(By.Id("button"),10);
btn.Click();
//This will wait up to 10 seconds until a button is found
var button = driver.FindElement(By.TagName("button"),10)
//This will wait up to 10 seconds until a button is found, and return all the buttons found
var buttonList = driver.FindElements(By.TagName("button"),10)
//This will wait for 10 seconds until we find at least 5 buttons
var buttonsMin= driver.FindElements(By.TagName("button"), 10, 5);
driver.Close();
This is the reusable function to wait for an element present in DOM using Explicit Wait.
Public void WaitForElement(IWebElement element, int timeout = 2){
WebDriverWait wait = new WebDriverWait(webDriver, TimeSpan.FromMinutes(timeout));
wait.IgnoreExceptionTypes(typeof(NoSuchElementException));
wait.IgnoreExceptionTypes(typeof(StaleElementReferenceException));
wait.Until<bool> (driver =>
{
try
{
return element.Displayed;
}
catch(Exception)
{
return false;
}
});
}
我们可以这样做：
public static IWebElement WaitForObject(IWebDriver DriverObj, By by, int TimeOut = 30)
{
try
{
WebDriverWait Wait1 = new WebDriverWait(DriverObj, TimeSpan.FromSeconds(TimeOut));
var WaitS = Wait1.Until(SeleniumExtras.WaitHelpers.ExpectedConditions.PresenceOfAllElementsLocatedBy(by));
return WaitS[0];
}
catch (NoSuchElementException)
{
Reports.TestStep("Wait for Element(s) with xPath was failed in current context page.");
throw;
}
}
使用Mike Kwan提供的解决方案可能会对整体测试性能产生影响，因为隐式等待将用于所有FindElement调用。很多时候，当元素不存在时，你会希望FindElement立即失败（你正在测试格式错误的页面，缺少元素等）。使用隐式等待，这些操作将在抛出异常之前等待整个超时到期。默认隐式等待设置为0秒。
我已经向IWebDriver写了一个小扩展方法，它为FindElement（）方法添加了一个超时（以秒为单位）参数。这是不言自明的：
public static class WebDriverExtensions
{
public static IWebElement FindElement(this IWebDriver driver, By by, int timeoutInSeconds)
{
if (timeoutInSeconds > 0)
{
var wait = new WebDriverWait(driver, TimeSpan.FromSeconds(timeoutInSeconds));
return wait.Until(drv => drv.FindElement(by));
}
return driver.FindElement(by);
}
}
我没有缓存WebDriverWait对象，因为它的创建非常便宜，这个扩展可以同时用于不同的WebDriver对象，我只在最终需要时进行优化。
用法很简单：
var driver = new FirefoxDriver();
driver.Navigate().GoToUrl("http://localhost/mypage");
var btn = driver.FindElement(By.CssSelector("#login_button"));
btn.Click();
var employeeLabel = driver.FindElement(By.CssSelector("#VCC_VSL"), 10);
Assert.AreEqual("Employee", employeeLabel.Text);
driver.Close();
WebDriverWait不会生效。
var driver = new FirefoxDriver(
new FirefoxOptions().PageLoadStrategy = PageLoadStrategy.Eager
);
driver.Navigate().GoToUrl("xxx");
new WebDriverWait(driver, TimeSpan.FromSeconds(60))
.Until(d => d.FindElement(By.Id("xxx"))); // a tag that close to the end
一旦页面“交互”，这将立即抛出异常。我不知道为什么但是超时就好像不存在一样。
也许SeleniumExtras.WaitHelpers工作，但我没有尝试。这是官方的，但被分成另一个nuget包。你可以参考C# Selenium 'ExpectedConditions is obsolete'。
我自己正在使用FindElements并检查Count == 0，如果是真的，使用await Task.Delay。这真的不是很有效率。
正在寻找如何在Selenium等待条件，登陆这个线程，这就是我现在使用的：
WebDriverWait wait = new WebDriverWait(m_driver, TimeSpan.FromSeconds(10));
wait.Until(d => ReadCell(row, col) != "");
ReadCell(row, col) != ""可以是任何条件。喜欢这种方式因为：
new WebDriverWait(driver, TimeSpan.FromSeconds(10)).
Until(ExpectedConditions.PresenceOfAllElementsLocatedBy((By.Id("toast-container"))));
第一个答案是好的，我的问题是未处理的异常没有正确关闭Web驱动程序，它保持我使用的第一个值，即1秒。
如果你遇到同样的问题
restart you visual studio并确保all the exceptions are handled正确。
你也可以使用
ExpectedConditions.ElementExists
因此，您将搜索这样的元素可用性
new WebDriverWait(driver, TimeSpan.FromSeconds(timeOut)).Until(ExpectedConditions.ElementExists((By.Id(login))));
这是@Loudenvier解决方案的变体，也适用于获取多个元素：
public static class WebDriverExtensions
{
public static IWebElement FindElement(this IWebDriver driver, By by, int timeoutInSeconds)
{
if (timeoutInSeconds > 0)
{
var wait = new WebDriverWait(driver, TimeSpan.FromSeconds(timeoutInSeconds));
return wait.Until(drv => drv.FindElement(by));
}
return driver.FindElement(by);
}
public static ReadOnlyCollection<IWebElement> FindElements(this IWebDriver driver, By by, int timeoutInSeconds)
{
if (timeoutInSeconds > 0)
{
var wait = new WebDriverWait(driver, TimeSpan.FromSeconds(timeoutInSeconds));
return wait.Until(drv => (drv.FindElements(by).Count > 0) ? drv.FindElements(by) : null);
}
return driver.FindElements(by);
}
}
受Loudenvier解决方案的启发，这是一个适用于所有ISearchContext对象的扩展方法，而不仅仅是IWebDriver，它是前者的特化。此方法还支持等待元素显示。
static class WebDriverExtensions
{
/// <summary>
/// Find an element, waiting until a timeout is reached if necessary.
/// </summary>
/// <param name="context">The search context.</param>
/// <param name="by">Method to find elements.</param>
/// <param name="timeout">How many seconds to wait.</param>
/// <param name="displayed">Require the element to be displayed?</param>
/// <returns>The found element.</returns>
public static IWebElement FindElement(this ISearchContext context, By by, uint timeout, bool displayed=false)
{
var wait = new DefaultWait<ISearchContext>(context);
wait.Timeout = TimeSpan.FromSeconds(timeout);
wait.IgnoreExceptionTypes(typeof(NoSuchElementException));
return wait.Until(ctx => {
var elem = ctx.FindElement(by);
if (displayed && !elem.Displayed)
return null;
return elem;
});
}
}
var driver = new FirefoxDriver();
driver.Navigate().GoToUrl("http://localhost");
var main = driver.FindElement(By.Id("main"));
var btn = main.FindElement(By.Id("button"));
btn.Click();
var dialog = main.FindElement(By.Id("dialog"), 5, displayed: true);
Assert.AreEqual("My Dialog", dialog.Text);
driver.Close();
我用谓词混淆了匿名函数。这是一个小帮手方法：
WebDriverWait wait;
private void waitForById(string id)
{
if (wait == null)
wait = new WebDriverWait(driver, new TimeSpan(0,0,5));
//wait.Until(driver);
wait.Until(d => d.FindElement(By.Id(id)));
}
你可以在C＃中找到类似的东西。
这就是我在JUnit中使用的 - Selenium
WebDriverWait wait = new WebDriverWait(driver, 100);
WebElement element = wait.until(ExpectedConditions.elementToBeClickable(By.id("submit")));
做导入相关的包
在Selenium IDE中选择Webdriver格式时，不会转换clickAndWait命令。这是解决方法。添加下面的等待行。实际上，问题是在我的C＃代码中的第1行之前发生的点击或事件。但实际上，只需确保在引用“By”对象的任何操作之前有WaitForElement。
HTML代码：
<a href="http://www.google.com">xxxxx</a>
C＃/ NUnit代码：
driver.FindElement(By.LinkText("z")).Click;
driver.WaitForElement(By.LinkText("xxxxx"));
driver.FindElement(By.LinkText("xxxxx")).Click();
from selenium import webdriver
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.common.by import By
driver.find_element_by_id('someId').click()
WebDriverWait(driver, timeout).until(EC.presence_of_element_located((By.ID, 'someAnotherId'))
从EC您可以选择其他条件尝试：http://selenium-python.readthedocs.org/api.html#module-selenium.webdriver.support.expected_conditions