How do I draw main view underneath my UINavigationBar so when the bar shows/hides, the view is unaffected? - ios

Question

Here's the situation:
I am making an app for iPad w/ iOS 6 using Autolayout along with UINavigationController. What I am trying to do is:
Segue from one view controller to the next with a standard push segue.
When I arrive at the new view controller, hide the nav bar with animation.
As the nav bar hides, I want my view to not shift at all. In fact, I want my view to effectively be drawn underneath the nav bar from the beginning, so I'm left with no shifting or movement of content and no black bars. For reference, this is what happens in the Amazon Kindle app when you go into a book.
With my current code, the contents of my view shift up to fill in the void left by the UINavigationBar.
I've tried force-setting the frame of my UIViewController's view and my UINavigationController's view to the entire iPad screen in the viewWillAppear method of my viewcontroller but no dice. I've experimented w/ Constraints in Autolayout but that also didn't get me to where I wanted to go.
Any help you can give would be great!

Answer 1

Try following before animating the navigation bar:
self.navigationController.navigationBar.alpha = 0.99f;
I didn't try this but this should work.

Answer 2

Looks like you need to add custom navigation bar in your new view and animate it to disappear.
I think, hiding original Navigation bar of Navigation Controller without shifting the view is not possible.
Rather add UINavigationBar to xib file, bind it to IBOutlet uiNavigationBar and try following code
-(void) viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[self.navigationController setNavigationBarHidden:YES animated:NO];
}
- (void) viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[UIView animateWithDuration:0.3f delay:0.0f options:UIViewAnimationOptionCurveEaseInOut animations:^{
CGRect f = self.uiNavigationBar.frame;
f.origin = CGPointMake(f.origin.x, f.origin.y - 44);
self.uiNavigationBar.frame = f;
} completion:^(BOOL finished) {
NSLog(#"done");
}];
}