元素不再附加到硒webdriver的DOM錯誤

Question

首先它正在執行else部分，然後在打印println後，它會發出此錯誤。不知道在退出循環後它是否發生錯誤。請幫忙。

Opens a page 
Check if the new month is available 
Downloads new month ex: Oct 
Then comes out of loop and should download Sep 

但是在出現循環後它會拋出上面的錯誤信息。

driver.get("http://www.depreportingservices.state.pa.us/ReportServer/Pages/ReportViewer.aspx?%2fOil_Gas%2fOil_Gas_Well_Historical_Production_Report"); 
      //maximizing the window 
       driver.manage().window().maximize(); 

       //WebElement select = driver.findElement(By.id("ReportViewerControl_ctl04_ctl03_ddValue")); 

       // Select select=new Select(select); 
       List<WebElement> options = driver.findElement(By.id("ReportViewerControl_ctl04_ctl03_ddValue")).findElements(By.tagName("option")); 
       //List <WebElement> Element1 = new ArrayList<WebElement>() ; 

       for(WebElement option : options){ 

        if(option.getText().equals("Sep 2015 (Unconventional wells)")) { 

         driver.get("http://www.depreportingservices.state.pa.us/ReportServer/Pages/ReportViewer.aspx?%2fOil_Gas%2fOil_Gas_Well_Historical_Production_Report"); 
         driver.wait(20000); 
          //options.wait(10000); 
          driver.findElement(By.id("ReportViewerControl_ctl04_ctl03_ddValue")); 

         System.out.println("old month"); 
         break; 

        } 
        else { 

        // if(option.getText().contains("Oct")) 
         //{ 
          System.out.println("Download new month"); 

          WebElement identifier = driver.findElement(By.xpath(".//*[@id='ReportViewerControl_ctl04_ctl03_ddValue']")); 
          Select select1 = new Select(identifier); 

          //select1.selectByVisibleText("Oct"); 

         select1.selectByVisibleText("Oct 2015 (Unconventional wells)"); 

          Wait(20000); 
          driver.findElement(By.xpath(".//*[@id='ReportViewerControl_ctl04_ctl00']")).click(); 
          Wait(70000); 
          //Click on File save button 
          driver.findElement(By.xpath(".//*[@id='ReportViewerControl_ctl05_ctl04_ctl00_Button']")).click(); 
          //wait time to load the options 
          Wait(20000); 
          driver.findElement(By.xpath(".//*[@id='ReportViewerControl_ctl05_ctl04_ctl00_Menu']/div[2]/a")).click(); 
          //fprofile.setPreference("browser.download.manager.showWhenStarting", false); 
          //fprofile.setPreference("pdfjs.disabled", true); 
          Wait(10000); 

         // driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS); 
          System.out.println("Oct month data downloaded in csv format"); 
          //driver.navigate().back(); 


         } 

Answer 1

該異常意味着您嘗試使用的元素不再存在於html中。

我的猜測是，您在for(WebElement option : options)上得到了例外，因爲else部分中的其中一個點擊會將您重定向到新頁面或從dom中刪除options。即使你回到上一頁，你仍然需要再次找到元素。

你可以嘗試這樣的事情

List<WebElement> options; 
int i = 0; 
do 
{ 
    options = driver.findElement(By.id("ReportViewerControl_ctl04_ctl03_ddValue")).findElements(By.tagName("option")); 
    if(options.get(i).getText().equals("Sep 2015 (Unconventional wells)")) 
    { 
    } 
    else() 
    { 
    } 
} while (i++ < options.size()) 

Answer 2

1. don't use wait 
    2. use css and not xpath 
    3 .read about page object design pattern 
    4 try to use this instead of the click 

after you clean your code you can find the problem easily 


    public static WebElement findElement(WebDriver driver, By selector, long timeOutInSeconds, String timeOutMessage) { 
      try { 
       WebDriverWait wait = new WebDriverWait(driver, timeOutInSeconds); 
       wait.until(ExpectedConditions.presenceOfElementLocated(selector)); 

       return findElement(driver, selector); 
      } catch (TimeoutException e) { 
       throw new IllegalStateException(timeOutMessage); 
      } 
     } 

     public static WebElement findElementSafe(WebDriver driver, By selector, long timeOutInSeconds) { 
      try { 
       return findElement(driver, selector, timeOutInSeconds); 
      } catch (TimeoutException e) { 
       return null; 
      } 
     }