navigation bar show/hide

Question

hi all, i want to hide and show navigation bar on double click. navigation bar consist of 2 bar buttons.

initially,navigation bar should be hidden. when user double taps the screen ,the navigation bar should come up with l'll animation,like we c in our iphone's photo gallery.

how can i do this,

suggestion are always appreciated

regards shishir

Answer 1

This isn't something that can fit into a few lines of code, but this is one approach that might work for you.

To hide the navigation bar:

[[self navigationController] setNavigationBarHidden:YES animated:YES];

To show it:

[[self navigationController] setNavigationBarHidden:NO animated:YES];

Documentation for this method is available here.

To listen for a "double click" or double-tap, subclass UIView and make an instance of that subclass your view controller's view property.

In the view subclass, override its -touchesEnded:withEvent: method and count how many touches you get in a duration of time, by measuring the time between two consecutive taps, perhaps with -timeIntervalSinceDate:. Or test the result from [touch tapCount].

If you get two taps, your subclassed view issues an NSNotification that your view controller has registered to listen for.

When your view controller hears the notification, it fires a selector that either hides or shows the navigation bar using the aforementioned code, depending on the navigation bar's current visible state, accessed through reading the navigation bar's isHidden property.