Hide navigation bar and toolbar on touch

Does anyone have any info or code on how to can hide a navigation bar and toolbar when the user touches the iphone screen.

Basically I have an image gallery and I want to see the images in the whole of the iphone screen.

also im trying to 开发者_如何学JAVAimplement a button so the user can download the image i had no luck on my search on google. Thanks

1. [self.navigationController setNavigationBarHidden:YES animated:YES]
2. as I remember, there is smth like setHidden: method for any view. toolbar is a view.
3. handling touches. see touchesBegan:withEvents: in UIResponder.
4. you cannot download image? how do you try to do it? what the problem is?