我尝试制作隐藏的FirefoxDriver。根据我的研究，我必须使用PhantomJSDriver，但是当我使用PhantomJSDriver
driver.FindElement语句不再起作用。

        var options = new PhantomJSOptions();       
        options.AddAdditionalCapability("phantomjs.page.settings.userAgent", 
        "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) 
        Chrome/40.0.2214.94 Safari/537.36");
        PhantomJSOptions p = new PhantomJSOptions();           
        var service = PhantomJSDriverService.CreateDefaultService();
        service.SslProtocol = "any";
        service.ProxyType = "http";
        service.WebSecurity = false;
        service.IgnoreSslErrors = true;
        var driver = new PhantomJSDriver(service, options);
        driver.Navigate().GoToUrl("https://www.google.com.tr/");
        Thread.Sleep(5000);
        driver.FindElement(By.XPath("//*[@id='lst-ib']")).SendKeys("edd");          
        string s = driver.Url;
        Console.WriteLine(s);

错误信息：

An unhandled exception of type ‘OpenQA.Selenium.NoSuchElementException’ occurred in WebDriver.dll

Additional information: {“errorMessage”:”Unable to find element with xpath ‘//[@id=’_fZl’]/span/svg/path’“,”request”:{“headers”:{“Accept”:”application/json, image/png”,”Connection”:”Close”,”Content-Length”:”57”,”Content-Type”:”application/json;charset=utf-8”,”Host”:”localhost:50454”},”httpVersion”:”1.1”,”method”:”POST”,”post”:”{"using":"xpath","value":"//[@id=’_fZl’]/span/svg/path"}”,”url”:”/element”,”urlParsed”:{“anchor”:”“,”query”:”“,”file”:”element”,”directory”:”/”,”path”:”/element”,”relative”:”/element”,”port”:”“,”host”:”“,”password”:”“,”user”:”“,”userInfo”:”“,”authority”:”“,”protocol”:”“,”source”:”/element”,”queryKey”:{},”chunks”:[“element”]},”urlOriginal”:”/session/feab13f0-720f-11e7-80b3-452aee308158/element”}}

还有其他隐藏FirefoxDriver的方法吗？请问你能帮帮我吗？