我发现的另一种方法是为NavigationController设置一个委托:

navigationController.delegate = self;

然后使用setNavigationBarHidden in navigationController:willShowViewController:animated:

- (void)navigationController:(UINavigationController *)navigationController 
      willShowViewController:(UIViewController *)viewController 
                    animated:(BOOL)animated 
{   
    // Hide the nav bar if going home.
    BOOL hide = viewController != homeViewController;
    [navigationController setNavigationBarHidden:hide animated:animated];
}

在一个地方为每个ViewController定制行为的简单方法。

我将把代码放在viewWillAppear委托中显示每个视图:

就像你需要隐藏它的地方:

- (void)viewWillAppear:(BOOL)animated
{
        [yourObject hideBar];
}

就像这样，你需要展示它:

- (void)viewWillAppear:(BOOL)animated
{
        [yourObject showBar];
}

在Swift 3中:

override func viewWillAppear(_ animated: Bool) {
    navigationController?.navigationBar.isHidden = true
    super.viewWillAppear(animated)
}


override func viewWillDisappear(_ animated: Bool) {
    if (navigationController?.topViewController != self) {
        navigationController?.navigationBar.isHidden = false
    }
    super.viewWillDisappear(animated)
}

经过多次试验，这里是我如何让它为我想要的工作。 这就是我一直在尝试的。 -我有一个图像视图。我想把图片全屏显示。 -我有一个导航控制器与选项卡太。所以我也要把它藏起来。 此外，我的主要要求不仅仅是隐藏，而且在显示和隐藏时也要有淡出效果。

这就是我让它工作的方法。

步骤1 -我有一个图像和用户点击该图像一次。我捕捉那个手势并把它推到新的imageViewController中，它在imageViewController中，我想要全屏图像。

- (void)handleSingleTap:(UIGestureRecognizer *)gestureRecognizer {  
NSLog(@"Single tap");
ImageViewController *imageViewController =
[[ImageViewController alloc] initWithNibName:@"ImageViewController" bundle:nil];

godImageViewController.imgName  = // pass the image.
godImageViewController.hidesBottomBarWhenPushed=YES;// This is important to note. 

[self.navigationController pushViewController:godImageViewController animated:YES];
// If I remove the line below, then I get this error. [CALayer retain]: message sent to deallocated instance . 
// [godImageViewController release];
} 

步骤2 -下面所有这些步骤都在ImageViewController中

步骤2.1 -在ViewDidLoad中，显示导航栏

- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
NSLog(@"viewDidLoad");
[[self navigationController] setNavigationBarHidden:NO animated:YES];
}

步骤2.2 -在viewDidAppear中，设置一个有延迟的定时器任务(我把它设置为1秒延迟)。并且在延迟之后，添加渐褪色效果。我用alpha来进行衰落。

- (void)viewDidAppear:(BOOL)animated
{
NSLog(@"viewDidAppear");

myTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self     selector:@selector(fadeScreen) userInfo:nil repeats:NO];
}

- (void)fadeScreen
{
[UIView beginAnimations:nil context:nil]; // begins animation block
[UIView setAnimationDuration:1.95];        // sets animation duration
self.navigationController.navigationBar.alpha = 0.0;       // Fades the alpha channel of   this view to "0.0" over the animationDuration of "0.75" seconds
[UIView commitAnimations];   // commits the animation block.  This Block is done.
}

步骤2.3 -在viewWillAppear下，添加singleTap手势到图像，并使导航栏半透明。

- (void) viewWillAppear:(BOOL)animated
{

NSLog(@"viewWillAppear");


NSString *path = [[NSBundle mainBundle] pathForResource:self.imgName ofType:@"png"];

UIImage *theImage = [UIImage imageWithContentsOfFile:path];

self.imgView.image = theImage;

// add tap gestures 
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)];  
[self.imgView addGestureRecognizer:singleTap];  
[singleTap release];  

// to make the image go full screen
self.navigationController.navigationBar.translucent=YES;
}

- (void)handleTap:(UIGestureRecognizer *)gestureRecognizer 
{ 
 NSLog(@"Handle Single tap");
 [self finishedFading];
  // fade again. You can choose to skip this can add a bool, if you want to fade again when user taps again. 
 myTimer = [NSTimer scheduledTimerWithTimeInterval:5.0 target:self  selector:@selector(fadeScreen) userInfo:nil repeats:NO];
 }

第三步-最后在viewWillDisappear中，确保把所有的东西放回去

- (void)viewWillDisappear: (BOOL)animated 
{ 
self.hidesBottomBarWhenPushed = NO; 
self.navigationController.navigationBar.translucent=NO;

if (self.navigationController.topViewController != self)
{
    [self.navigationController setNavigationBarHidden:NO animated:animated];
}

[super viewWillDisappear:animated];
}

我相信@chad-m的回答。

以下是Swift版本:

创建一个新文件MyNavigationController.swift

import UIKit

class MyNavigationController: UINavigationController, UINavigationControllerDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        self.delegate = self
    }

    func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
        if viewController == self.viewControllers.first {
            self.setNavigationBarHidden(true, animated: animated)
        } else {
            self.setNavigationBarHidden(false, animated: animated)
        }
    }

}

在StoryBoard中将UINavigationController的类设置为MyNavigationController 就是这样!

chad-m的回答和我的不同之处在于:

继承自UINavigationController，所以你不会污染你的rootViewController。 使用self.viewControllers.first而不是homeViewController，这样你就不会为你的100个UINavigationControllers在一个StoryBoard中做100次。

斯威夫特4:

在你想要隐藏导航栏的视图控制器中。

override func viewWillAppear(_ animated: Bool) {
    self.navigationController?.setNavigationBarHidden(true, animated: animated)
    super.viewWillAppear(animated)
}

override func viewWillDisappear(_ animated: Bool) {
    self.navigationController?.setNavigationBarHidden(false, animated: animated)
    super.viewWillDisappear(animated)
}