Gets the URI of the parent category of this chat room. Chat rooms are organized hierarchically into categories. Each category may contain any number of chat rooms, as well as other sub-categories. Each chat room and category in the system has precisely one parent category. There is a single top-level chat room category, called the root category, which is referenced by the RootCategoryUri . To change the parent category, use BeginChangeParentCategory(ChatRoom, Uri, AsyncCallback, Object) .