HtmlUnit JavaScript事件

我已成功在SITE上使用HtmlUnit登录，运行了表单搜索并获得了包含结果的页面.现在在现实世界中，要获得整个页面的结果，我需要滚动页面更多次.但是我正在使用HtmlUnit，然后我已经完成了:

I successfull done login with HtmlUnit on SITE, run a form search and got a page with results. Now in real world, to get the whole page result I need to scroll the page more times . But I am using HtmlUnit ,then I have done :

List<DIV> res=page.getByXPath(...) // got 13 items
ScriptResult res=page.executeJavaScript("window.scrollBy (0,2000);");
res=page.getByXPath(...) // would get other items,same query as the first

问题在于，在上面的代码返回与运行JS之前相同的项目之后，页面上的查询返回的结果与XPath查询相同.相反，在浏览器上，滚动效果很好，并返回结果项目的seconf列.那么，HtmlUnit不是为此设计的吗?一个错误?还是还有另一个HtmlUnit技巧?

The problem is that the query on page , after the above code is returning the same items as before run JS , the XPath query return same result items . Instead ,on browser, the scroll work well and return the seconf train of result items. Then , does HtmlUnit is not designed for this ? a bug ? or there is another HtmlUnit trick?

我也尝试过

ScriptResult res =page.getBody().fireEvent("scroll");

谢谢