使用导航栏

导航栏包含导航按钮，导航控制器，这是一个堆栈视图控制器，可入栈和出栈。标题导航栏上的标题是当前视图的控制器

示例代码和步骤

1. 创建一个视图的应用程序

2. 现在选择APP Delegate.h，添加一个属性，导航控制器如下

#import <UIKit/UIKit.h>

@class ViewController;

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;

@property (strong, nonatomic) ViewController *viewController;

@property (strong, nonatomic) UINavigationController *navController;

@end

3. 现在更新应用：didFinishLaunchingWithOptions 方法在 AppDelegate.m 文件分配导航控制器，使窗口的根视图控制器如下：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:
    [[UIScreen mainScreen] bounds]];
    // Override yiibai for customization after application launch.
    self.viewController = [[ViewController alloc] 
    initWithNibName:@"ViewController" bundle:nil];
    //Navigation controller init with ViewController as root
    UINavigationController *navController = [[UINavigationController alloc]
    initWithRootViewController:self.viewController];
    self.window.rootViewController = navController;
    [self.window makeKeyAndVisible];
    return YES;
}

4.现在，添加新的类文件TempViewController通过选择File -> New ->File... -> Objective C Class，UIViewController 的子类命名类为 TempViewController。

5. 添加一个UIButton navButon 在ViewController.h 如下

// ViewController.h
#import <UIKit/UIKit.h>

@interface ViewController : UIViewController
{    
    UIButton *navButton;
}
@end

6. 现在添加一个方法 addNavigationBarItem 并在 viewDidLoad 中调用此方法。

7. 创建导航项目动作的方法。

8. 我们还需要另一种方法来创建另一个视图控制器TempViewController的推送。

9. 更新后的 ViewController.m 如下

// ViewController.m
#import "ViewController.h"
#import "TempViewController.h"
@interface ViewController ()

@end
@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self addNavigationBarButton];
    //Do any additional setup after loading the view, typically from a nib
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(IBAction)pushNewView:(id)sender{
   TempViewController *tempVC =[[TempViewController alloc]
   initWithNibName:@"TempViewController" bundle:nil];
   [self.navigationController pushViewController:tempVC animated:YES];
}

-(IBAction)myButtonClicked:(id)sender{
   // toggle hidden state for navButton
   [navButton setHidden:!nav.hidden];
}

-(void)addNavigationBarButton{
   UIBarButtonItem *myNavBtn = [[UIBarButtonItem alloc] initWithTitle:
   @"MyButton" style:UIBarButtonItemStyleBordered target:
   self action:@selector(myButtonClicked:)];
   
   [self.navigationController.navigationBar setBarStyle:UIBarStyleBlack];
   [self.navigationItem setRightBarButtonItem:myNavBtn];
   
   // create a navigation push button that is initially hidden
   navButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
   [navButton setFrame:CGRectMake(60, 50, 200, 40)];
   [navButton setTitle:@"Push Navigation" forState:UIControlStateNormal];
   [navButton addTarget:self action:@selector(pushNewView:) 
   forControlEvents:UIControlEventTouchUpInside];
   [self.view addSubview:navButton];
   [navButton setHidden:YES];
}
@end

10. 现在，当我们运行程序时，我们会得到下面的输出

11. 点击导航按钮MyButton，推送导航按钮切换能见度

12. 点击推导航按钮按下另一个视图控制器，如下图所示。