javascript - 使用 C# 在 Selenium 页面对象模型中不可能实现鼠标悬停

Question

我需要将鼠标悬停在网站的菜单选项上，以便出现上下文菜单。所以我尝试了这两种方法:使用 Actions-Class 并在我的 Page-Object-Model-Selenium 项目中使用 Pagefactory 的专用脚本使用 JavaScriptExecutor。但事实证明，它们在 POM 中都会抛出异常，而在非 POM Selenium 项目中则不会。我提供了两个简单的示例，以便您可以自己比较这些行为。

下面是没有 POM 的版本，它可以工作:

using System;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using OpenQA.Selenium.Support.Events;
using OpenQA.Selenium.Remote;
using OpenQA.Selenium;
using OpenQA.Selenium.Interactions;

namespace UnitTestProject1
{
[TestClass]
public class SimpleTest
{
    public static EventFiringWebDriver Driver { get; set; }

    [TestMethod]
    public void TestMethod1()
    {
        var caps = new DesiredCapabilities();
        caps.SetCapability("browserName", "internet explorer");
        SimpleTest.Driver = new EventFiringWebDriver(new RemoteWebDriver(new Uri("http://127.0.0.1:4444/wd/hub"), caps, TimeSpan.FromSeconds(120)));
        SimpleTest.Driver.Navigate().GoToUrl("https://www.stackoverflow.com");
        var element = SimpleTest.Driver.FindElement(By.Id("nav-questions"));

        // using Actions
        // does not throw an exception
        new Actions(SimpleTest.Driver).MoveToElement(element).Perform();

        // using JavaScript
        // does not throw an exception
        var mouseOverScript = @"if(document.createEvent){var evObj = document.createEvent('MouseEvents');evObj.initEvent('mouseover', true, false); arguments[0].dispatchEvent(evObj); } else if(document.createEventObject) { arguments[0].fireEvent('onmouseover'); }";
        ((IJavaScriptExecutor)SimpleTest.Driver).ExecuteScript(mouseOverScript, element);
    }

    [TestCleanup]
    public void Cleanup()
    {
        SimpleTest.Driver.Quit();
    }
}
}

这是带有 POM 的版本，它只抛出异常，即使其他一切都与其他示例中的相同:

using System;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using OpenQA.Selenium.Support.Events;
using OpenQA.Selenium.Remote;
using OpenQA.Selenium;
using OpenQA.Selenium.Interactions;
using OpenQA.Selenium.Support.PageObjects;

namespace UnitTestProject1
{
[TestClass]
public class PomTest
{
    public PomTest()
    {
        var caps = new DesiredCapabilities();
        caps.SetCapability("browserName", "chrome");
        PomTest.Driver = new EventFiringWebDriver(new RemoteWebDriver(new Uri("http://127.0.0.1:4444/wd/hub"), caps, TimeSpan.FromSeconds(120)));
        PomTest.Driver.Navigate().GoToUrl("https://www.stackoverflow.com");
    }

    public static EventFiringWebDriver Driver { get; set; }

    [TestMethod]
    public void TestMethod1()
    {
        var page = new SoPage();
        page.HoverWithActions();
        page.HoverWithJS();
    }

    [TestCleanup]
    public void Cleanup()
    {
        PomTest.Driver.Quit();
    }
}

public class SoPage
{
    public SoPage()
    {
        PageFactory.InitElements(PomTest.Driver, this);
    }

    public void HoverWithActions()
    {
        // using Actions
        // throws System.Reflection.TargetException;
        new Actions(PomTest.Driver).MoveToElement(this.Element).Perform();
    }

    public void HoverWithJS()
    {
        // using JavaScript
        // throws System.ArgumentException
        var mouseOverScript = @"if(document.createEvent){var evObj = document.createEvent('MouseEvents');evObj.initEvent('mouseover', true, false); arguments[0].dispatchEvent(evObj); } else if(document.createEventObject) { arguments[0].fireEvent('onmouseover'); }";
        ((IJavaScriptExecutor)PomTest.Driver).ExecuteScript(mouseOverScript, this.Element);
    }

    [FindsBy(How = How.Id, Using = "nav-questions")]
    public IWebElement Element { get; set; }
}
}

操作的异常(exception)情况是:

"System.Reflection.TargetException: Das Objekt stimmt mit dem Zieltyp nicht überein.
   bei System.Reflection.RuntimeMethodInfo.CheckConsistency(Object target)
   bei System.Reflection.RuntimeMethodInfo.InvokeArgumentsCheck(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   bei System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   bei OpenQA.Selenium.Support.PageObjects.WebDriverObjectProxy.InvokeMethod(IMethodCallMessage msg, Object representedValue)
   bei OpenQA.Selenium.Support.PageObjects.WebElementProxy.Invoke(IMessage msg)
   bei System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   bei OpenQA.Selenium.ILocatable.get_Coordinates()
   bei OpenQA.Selenium.Interactions.Internal.MouseAction.get_ActionLocation()
   bei OpenQA.Selenium.Interactions.MoveMouseAction.Perform()
   bei OpenQA.Selenium.Interactions.CompositeAction.Perform()
   bei OpenQA.Selenium.Interactions.Actions.Perform()
   bei UnitTestProject1.SoPage.HoverWithActions() in c:\\users\\lwa\\documents\\visual studio 2015\\Projects\\UnitTestProject1\\UnitTestProject1\\PomTest.cs:Zeile 50.
   bei UnitTestProject1.PomTest.TestMethod1() in c:\\users\\lwa\\documents\\visual studio 2015\\Projects\\UnitTestProject1\\UnitTestProject1\\PomTest.cs:Zeile 28."

这对于 JavaScriptExecutor 来说:

System.ArgumentException: Argument is of an illegal typeOpenQA.Selenium.Support.Events.EventFiringWebDriver+EventFiringWebElement
Parametername: arg
   bei OpenQA.Selenium.Remote.RemoteWebDriver.ConvertObjectToJavaScriptObject(Object arg)
   bei OpenQA.Selenium.Remote.RemoteWebDriver.ConvertArgumentsToJavaScriptObjects(Object[] args)
   bei OpenQA.Selenium.Remote.RemoteWebDriver.ExecuteScriptCommand(String script, String commandName, Object[] args)
   bei OpenQA.Selenium.Remote.RemoteWebDriver.ExecuteScript(String script, Object[] args)
   bei OpenQA.Selenium.Support.Events.EventFiringWebDriver.ExecuteScript(String script, Object[] args)
   bei UnitTestProject1.SoPage.HoverWithJS() in c:\\users\\lwa\\documents\\visual studio 2015\\Projects\\UnitTestProject1\\UnitTestProject1\\PomTest.cs:Zeile 58.
   bei UnitTestProject1.PomTest.TestMethod1() in c:\\users\\lwa\\documents\\visual studio 2015\\Projects\\UnitTestProject1\\UnitTestProject1\\PomTest.cs:Zeile 29."

我在 Visual Studio 2015 中使用 C#，并在版本 3.3 中使用 Selenium.WebDriver 和 Selenium.Support 包，有一个错误阻止我使用 3.4(请参阅 this question )。我的 Selenium 服务器独立版是 3.4.0。 Chrome、Firefox 和 Internet Explorer 的行为相同。

有人知道如何在 C# 的 POM 项目中实现悬停吗？

Answer 1

我找到了两个解决方法。您可以放弃 FindsByAttribute 并自己定义一个属性 getter

public IWebElement Element => PomTest.Driver.FindElement(By.Id("nav-questions"));

或者您可以使用 IWebElements 的 IList 来代替 IWebElement，然后引用列表的第一个元素，此选项的功劳归于 this question 。 这将是我正在使用的变体，它看起来像这样:

public void HoverWithActions()
{
    // using actions
    // now it works :)
    new Actions(PomTest.Driver).MoveToElement(this.Elements.First()).Perform();
}

public void HoverWithJS()
{
    // using Javascript
    // now it works :)
    var mouseOverScript = @"if(document.createEvent){var evObj = document.createEvent('MouseEvents');evObj.initEvent('mouseover', true, false); arguments[0].dispatchEvent(evObj); } else if(document.createEventObject) { arguments[0].fireEvent('onmouseover'); }";
    ((IJavaScriptExecutor)PomTest.Driver).ExecuteScript(mouseOverScript, this.Elements.First());
}

[FindsBy(How = How.Id, Using = "nav-questions")]
public IList<IWebElement> Elements { get; set; }