尝试Catch WebDriverTimeoutException不起作用

Question

我的try catch块中有2个catch，但WebDriverTimeoutException根本没有被捕获。另一个例外是正确捕获。超时异常测试失败＆＃34; OpenQA.Selenium.WebDriverTimeoutException：20秒后超时＆＃34;

那么为什么WebDriverTimeoutException try catch根本没被捕获呢？

    public IWebElement FindElement(By howBy)
    {

        TimeSpan _elementTimeOut = TimeSpan.FromSeconds(20);


        IWebElement elementfound = null;

        WebDriverWait wait = new WebDriverWait(WebDriver, _elementTimeOut);
        wait.Until<IWebElement>(d =>
        {
            try
            {
                elementfound = WebDriver.FindElement(howBy);
            }
            catch (WebDriverTimeoutException f)
            {
                Console.WriteLine("Please fail WebDriverTimeoutException");
            }
            catch (NoSuchElementException e)
            {
                Console.WriteLine("Please fail NoSuchElementException");
            }

            return elementfound;
        });

        return elementfound;
  }

Answer 1

在WebDriverTimeoutException块内的匿名方法中未捕获Until()的原因是匿名方法不会抛出异常。您需要捕获超时外部 Until()方法。即：

public IWebElement FindElement(IWebDriver driver, By howBy)
{
    TimeSpan elementTimeOut = TimeSpan.FromSeconds(20);
    IWebElement elementfound = null;

    try
    {
        WebDriverWait wait = new WebDriverWait(driver, elementTimeOut);
        elementFound = wait.Until<IWebElement>(d =>
        {
            try
            {
                elementfound = driver.FindElement(howBy);
            }
            catch (NoSuchElementException e)
            {
                Console.WriteLine("Please fail NoSuchElementException");
            }

            return elementfound;
        });
    }
    catch (WebDriverTimeoutException)
    {
        Console.WriteLine("Please fail WebDriverTimeoutException");
    }

    return elementfound;
}

进一步注意WebDriverWait已经捕获NoSuchElementException作为其正常操作的一部分，所以你用你的例子重新发明轮子。执行相同操作的更紧凑和有效的方法如下所示：

public IWebElement FindElement(IWebDriver driver, By howBy)
{
    TimeSpan elementTimeOut = TimeSpan.FromSeconds(20);
    IWebElement elementfound = null;

    try
    {
        WebDriverWait wait = new WebDriverWait(driver, elementTimeOut);
        elementFound = wait.Until<IWebElement>(d => driver.FindElement(howBy));
    }
    catch (WebDriverTimeoutException)
    {
        Console.WriteLine("Please fail WebDriverTimeoutException");
    } 

    return elementfound;
}