运行测试时出现此错误：org.openqa.selenium.StaleElementReferenceException：元素不再附加到 DOM
关于如何解决上述异常的任何想法？这发生在我的网格中，它有一个动态的 ref Xpath 表达式
Selenium WebDriver StaleElementReferenceException
IT小君
2021-10-25T02:50:29
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评论(11)
IT小君 我们通过做一些叫做 WebdriverWrapper 和 WebElementWrapper 的事情来解决这个问题。
这些包装器的作用是处理内部的 StaleElementException，然后使用定位器重新评估并获取新的 WebElement 对象。这样，您需要将处理异常的代码散布在整个代码库中，并将其本地化为一个类。
我很快就会研究这两个类的开源，如果大家有兴趣，我会在此处添加一个链接。
2021-10-25T02:50:30
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IT小君 当您尝试使用页面上不再存在的 WebElement 方法时，将引发该异常。如果您的网格正在动态加载数据并且您刷新了网格，则对该网格上元素的任何引用都将是“陈旧的”。仔细检查您尝试引用的元素是否在测试中的页面上，并且您可能需要重新实例化该对象。
2021-10-25T02:50:30
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IT小君 它也遇到了这个问题，看起来很明显模态面板加载陷入竞争状态并一直等待直到超时。
我已经尝试了很多次，发现解决方案是保持模式面板加载，直到它可以被 webDriver 准确找到，同时保持刷新 webDriver 实例，然后尝试在模式面板中找到 WebElements。
所以解决方案如下：例如MyModalPanel是您的ModalPanel Id，然后执行以下操作
page.openModalPanel();
Assert.assertTrue(page.waitTillDisplay( "MyModalPanelContentDiv"), Wait.MODAL_PANEL));
page.fillInFormInModalpanel(formObj);
而waitTillDisplay代码可以在WebDriver网站上找到，我将我的代码贴在这里供您参考：
public Boolean waitTillDisplay(final String id, int waitSeconds){
WebDriverWait wait = new WebDriverWait(driver, waitSeconds);
Boolean displayed = wait.until(new ExpectedCondition<Boolean>() {
public Boolean apply(WebDriver driver) {
return driver.findElement(By.id(id)).isDisplayed();
}
});
return displayed;
}
2021-10-25T02:50:30
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IT小君 您可能会在单击元素后尝试获取任何元素属性。
我遇到了同样的问题，我试图在单击按钮后获取按钮的 getText()。就我而言，一旦单击按钮，就会出现新窗口。
2021-10-25T02:50:30
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IT小君 我使用了 FluentWait 和 ExpectedCondition 应用覆盖：https ://gist.github.com/djangofan/5112655 。这个处理最终块内的异常，不像其他人如何回答这个，并允许将连续尝试包装在该块中。我认为这更优雅。
public static void clickByLocator( final By locator ) {
final long startTime = System.currentTimeMillis();
driver.manage().timeouts().implicitlyWait( 5, TimeUnit.SECONDS );
Wait<WebDriver> wait = new FluentWait<WebDriver>( driver )
.withTimeout(90000, TimeUnit.MILLISECONDS)
.pollingEvery(5500, TimeUnit.MILLISECONDS);
//.ignoring( StaleElementReferenceException.class );
wait.until( new ExpectedCondition<Boolean>() {
@Override
public Boolean apply( WebDriver webDriver ) {
try {
webDriver.findElement( locator ).click();
return true;
} catch ( StaleElementReferenceException e ) { // try again
return false;
}
}
} );
driver.manage().timeouts().implicitlyWait( DEFAULT_IMPLICIT_WAIT, TimeUnit.SECONDS );
long endTime = System.currentTimeMillis();
long totalTime = endTime - startTime;
log("Finished click after waiting for " + totalTime + " milliseconds.");
}
2021-10-25T02:50:31
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IT小君 public static Boolean executeElementSendKeys
(WebDriver driver, WebElement element, String sInputParameters) throws Exception {
return (Boolean) executeElementMaster
(driver, element, "sendKeys", sInputParameters, 30, true);
}
public static Boolean executeElementClear
(WebDriver driver, WebElement element) throws Exception {
return (Boolean) executeElementMaster (driver, element, "clear", "", 30, true);
}
public static String executeElementGetText
(WebDriver driver, WebElement element) throws Exception {
return (String) executeElementMaster (driver, element, "getText", "", 30, true);
}
public static Boolean executeElementClick
(WebDriver driver, WebElement element) throws Exception {
return (Boolean) executeElementMaster (driver, element, "click", "", 30, true);
}
public static boolean executeElementIsDisplayed
(WebDriver driver, WebElement element) throws Exception {
return (Boolean) executeElementMaster (driver, element, "isDisplayed", "", 30, true);
}
public static String executeElementGetAttribute
(WebDriver driver, WebElement element, String sInputParameters) throws Exception {
return (String) executeElementMaster
(driver, element, "getAttribute", sInputParameters, 30, true);
}
// 下面是处理StaleElementReferenceException和其他异常的主方法。
//在闭锁段，替换(Exception e)用(StaleElementReferenceException e)，如果你想只此方法重试操作（如点击，等的SendKeys） StaleElementReferenceException，而不是其他异常。
private static Object executeElementMaster(WebDriver driver, WebElement element, String sExecuteAction, String sInputParametersOptional, int MaxTimeToWait,
boolean bExpectedElementState) throws Exception {
try {
// Local variable declaration
String sElementString = "";
String sElementXpath = "";
Object ReturnValue = "";
int Index = 0;
boolean bCurrentElementState = true;
boolean bWebDriverWaitUntilElementClickableFlag = false;
System.out.println("**** Execute method '" + sExecuteAction + "' on '" + sElementString + "' - Expected : '" + bExpectedElementState + "'");
System.out.println("**** MaxTimeToWait ='" + MaxTimeToWait + "' seconds");
// Set browser timeout to 1 second. Will be reset to default later
driver.manage().timeouts().implicitlyWait(1, TimeUnit.SECONDS);
// Keep trying until 'MaxTimeToWait' is reached
for (int i = 0; i < MaxTimeToWait; i++) {
try {
// Get element xPath - and find element again
if (element != null && i < 2 && sElementString == "") {
sElementString = (element).toString();
if (sElementString.contains("xpath: ")) {
// Retrieve xPath from element, if available
Index = sElementString.indexOf("xpath: ");
sElementXpath = sElementString.substring(Index + 7, sElementString.length());
}
}
// Find Element again
if (sElementXpath != "" && i > 0) {
element = driver.findElement(By.xpath(sElementXpath));
}
// Execute the action requested
switch (sExecuteAction) {
case ("isDisplayed"):
// Check if element is displayed and save in bCurrentElementState variable
ReturnValue = element.isDisplayed();
bCurrentElementState = (Boolean) ReturnValue;
bWebDriverWaitUntilElementClickableFlag = true;
break;
case ("getText"):
ReturnValue = element.getText();
bCurrentElementState = true;
bWebDriverWaitUntilElementClickableFlag = false;
break;
case ("sendKeys"):
// Scroll element into view before performing any action
element.sendKeys(sInputParametersOptional);
ReturnValue = true;
bCurrentElementState = true;
bWebDriverWaitUntilElementClickableFlag = false;
break;
case ("clear"):
// Scroll element into view before performing any action
element.clear();
ReturnValue = true;
bCurrentElementState = true;
bWebDriverWaitUntilElementClickableFlag = false;
break;
case ("click"):
// Scroll element into view before performing any action
element.click();
ReturnValue = true;
bCurrentElementState = true;
bWebDriverWaitUntilElementClickableFlag = false;
break;
default:
ReturnValue = element.getAttribute(sInputParametersOptional);
bCurrentElementState = true;
break;
}
} catch (Exception e) {
Thread.sleep(500);
bCurrentElementState = false;
ReturnValue = false;
}
if (bCurrentElementState == bExpectedElementState) {
// If element's actual and expected states match, log result and return value
System.out.println("**** PASSED: Execute method '" + sExecuteAction + "' on '" + sElementString + "' - Returned '" + ReturnValue + "' **** \n"
+ "Actual element status: '" + bCurrentElementState + "' Expected element status: '" + bExpectedElementState + "'");
break;
} else {
// If element's actual and expected states do NOT match, loop until they match or timeout is reached
Thread.sleep(500);
}
}
// Reset browser timeout to default
driver.manage().timeouts().implicitlyWait(3, TimeUnit.SECONDS);
// Return value before exiting
if (bCurrentElementState != bExpectedElementState) {
// If element's actual and expected states do NOT match, log result and return value
System.out.println("**** FAILED: Execute method '" + sExecuteAction + "' on '" + sElementString + "' - Returned '" + ReturnValue + "' **** \n"
+ "Actual element status: '" + bCurrentElementState + "' Expected element status: '" + bExpectedElementState + "'");
if (sExecuteAction.equalsIgnoreCase("findElement")) {
ReturnValue = null;
}
}
return ReturnValue;
} catch (Exception e) {
System.out.println("Exception in executeElementMaster - " + e.getMessage());
throw (e);
}
}
2021-10-25T02:50:31
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IT小君 我做了一些更改以更加灵活：
delegate void StaleFunction(IWebElement elt);
private static void StaleElementHandleByID(By by, StaleFunction func )
{
int count = 0;
while (count < 4)
{
try
{
IWebElement yourSlipperyElement = Driver.FindElement(by);
func(yourSlipperyElement);
count = count + 4;
}
catch (StaleElementReferenceException e)
{
count = count + 1;
}
}
}
StaleElementHandleByID(By.Id("identDdl"),
delegate(IWebElement elt)
{
SelectElement select = new SelectElement(elt);
select.SelectByText(tosave.ItemEquipamentoCem.CodigoCne.ToString());
});
2021-10-25T02:50:31
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IT小君 一个快速而肮脏的解决方案：
el.click()
time.sleep(1)
然后继续以迭代方式解析
2021-10-25T02:50:32
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IT小君 在这种情况下，测试正在寻找尚未加载或已刷新的元素。因此，出现了 StaleElementException。一个简单的解决方案是添加一个fluentWait。
2021-10-25T02:50:32
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IT小君 @netz75：谢谢。单击重定向到第二页时出现此问题。这对我有用：
//.. (first page asserts)
//...
element.Click();
Thread.Sleep(200);
//.. (second page asserts)
//...
2021-10-25T02:50:32
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我遇到了同样的问题，找不到任何解决方案。想出一个解决方案并将其张贴在这里，希望这可以帮助遇到同样问题的人。我创建了一个类来根据它们的类型、cssselector、id 等处理陈旧元素，并像调用任何其他页面对象一样简单地调用它。
public void StaleElementHandleByID (String elementID) { int count = 0; boolean clicked = false; while (count < 4 && !clicked) { try { WebElement yourSlipperyElement= driver.findElement(By.id(elementID)); yourSlipperyElement.click(); clicked = true; } catch (StaleElementReferenceException e) { e.toString(); System.out.println("Trying to recover from a stale element :" + e.getMessage()); count = count+1; } } }我建议仅在您知道会导致 WebDriver 出现问题的元素上使用它。