PHantom JS 50％的时间都失败了
我搜索一个文本框，然后尝试用字符串填充它。 这是代码：
var fname = _driver.FindElement(By.Name("iFirstName"), 50); if(fname!=null) { do { System.Threading.Thread.Sleep(500); } while (!fname.Displayed); fname.SendKeys(myName); } FindElement函数是这样的：
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); }
有些时候文本框中填充了字符串，有时我收到此错误：
System.InvalidOperationException: {"errorMessage":"'undefined' is not an object (evaluating '(y(a)?y(a).parentWindow||y(a).defaultView:window).getComputedStyle(a,null).MozTransform.match')","request":{"headers":{"Accept":"application/json, image/png","Connection":"Close","Host":"localhost:59868"},"httpVersion":"1.1","method":"GET","url":"/displayed","urlParsed":{"anchor":"","query":"","file":"displayed","directory":"/","path":"/displayed","relative":"/displayed","port":"","host":"","password":"","user":"","userInfo":"","authority":"","protocol":"","source":"/displayed","queryKey":{},"chunks":["displayed"]},"urlOriginal":"/session/af970250-310e-11e4-8996-210a8c2c5f2a/element/%3Awdc%3A1409489997045/displayed"}} at OpenQA.Selenium.Remote.RemoteWebDriver.UnpackAndThrowOnError(Response errorResponse) in c:\Projects\webdriver\dotnet\src\webdriver\Remote\RemoteWebDriver.cs:line 1048 at OpenQA.Selenium.Remote.RemoteWebDriver.Execute(String driverCommandToExecute, Dictionary`2 parameters) in c:\Projects\webdriver\dotnet\src\webdriver\Remote\RemoteWebDriver.cs:line 865 at OpenQA.Selenium.Remote.RemoteWebElement.get_Displayed() in c:\Projects\webdriver\dotnet\src\webdriver\Remote\RemoteWebElement.cs:line 187
这有什么问题？ 我甚至在调用所有上述函数之前制作了一个打印屏幕，并且所有元素都被正确绘制，因此页面被正确加载。
问题是我正在设置从列表中随机生成的自定义UserAgent，其中一些UserAgent（Internet Explorer）导致错误：
PhantomJSOptions options = new PhantomJSOptions(); int header = GenerateRandomBetween(0,phantomHeader.Count-1); options.AddAdditionalCapability("phantomjs.page.settings.userAgent", phantomHeader[header]);
我删除了它们，现在我不再获得例外。