How to hide/show paragraphs programmatically?

[Chriz]

Hi all,
I am a newbie to OO and now I am working on a project in Java. I want to use the UNO API to hide the specific paragraphs in the editor view. I've already got the paras' enumeration, but dont know what to do next.
I've found a thread http://api.openoffice.org/servlets/ReadMsg?listName=dev&msgNo=8993 talking about this question. However I cannot create a TextSection instance. Below is my code snippet:
XMultiServiceFactory factory = (XMultiServiceFactory) UnoRuntime
.queryInterface(XMultiServiceFactory.class, xTDoc);
XTextSection section = factory.createInstance("com.sun.star.text.TextSection");//interrupt at this line, the factory is not null in the debug view.

So is there anything wrong with the creation of TextSection? Or is there any way to hide/show the paragraphs?
Thanks.
_________________
Chris

[Chriz]

I know the problem. It is because of the casting method in OO, the below code works:
XTextSection textSection = (XTextSection) UnoRuntime.queryInterface(XTextSection.class,factory.createInstance("com.sun.star.text.TextSection"));


However this method seems not perfect, because when I set the IsVisible property true, there comes out a border round each textsection. This is different from the original view of those paragraphs. So back to my question, is there any good way to programmatically hide/show paragraphs?

Thank you all.
_________________
Chris