How many UINavigationController objects in a single iPhone application?

I think one of my design problems is that I keep creating navigation objects when I should only have one UINavigationController and a delegate. Is that correct?

I not as concerned from a style-preference, but the answer I am looking for is more about the a technical perspective and managing the navigation among several view controllers. Any pointe开发者_Python百科rs are very much appreciated and recognized.

I continue to think that I have the SDK under control and then I struggle again.

OK ... I am re-reading Apple's Dev Doc and the answer is 'usually only one, but quite often more than one.'

"iPhone Dev Center: View Controller Programming Guide for iPhone OS: Introduction"

"It makes the most sense to include navigation controllers in your application’s main nib file. You do this when the navigation controller itself provides the main view for your application’s window or in situations where the navigation controller provides the root view for a tab bar interface. Although you could also load standalone or modally presented navigation controllers from your main nib file (or any other nib file), doing so is not optimal. In those scenarios, it is usually easier to create the navigation controller programmatically at the point of use."