UIBarbuttonItem

APPDelegate:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];

    //创建主界面，导航栏的第一个页面

    FirstViewController *fvc = [[FirstViewController alloc]init];

    

    //创建一个导航栏控制器

    UINavigationController *nav = [[UINavigationController alloc]initWithRootViewController:fvc];

    nav.navigationBar.barTintColor = [UIColor redColor];

    self.window.rootViewController = nav;//设置根控制器

    [self.window makeKeyAndVisible];

    return YES;

}

//给导航栏添加左右按钮

    UIBarButtonItem *cancelButton = [[UIBarButtonItem alloc]initWithTitle:@"cancel" style:UIBarButtonItemStyleDone target:nil action:nil];

    self.navigationItem.leftBarButtonItem = cancelButton;

    self.navigationItem.leftBarButtonItem.tintColor = [UIColor whiteColor];

    

    UIBarButtonItem *nextButton = [[UIBarButtonItem alloc]initWithTitle:@"next" style:UIBarButtonItemStyleDone target:self action:@selector(goToSecond)];

    self.navigationItem.rightBarButtonItem = nextButton ;

    self.navigationItem.rightBarButtonItem.tintColor = [UIColor whiteColor];

    

    UILabel *yLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, 100, 44)];

    yLabel.backgroundColor = [UIColor yellowColor];

    yLabel.text = @"新浪";

    yLabel.font = [UIFont systemFontOfSize:22];

    yLabel.textColor = [UIColor redColor];

    yLabel.textAlignment = NSTextAlignmentCenter;

    self.navigationItem.titleView = yLabel;

-(void)goToSecond{

    //创建即将显示的界面

    SecondViewController *svc = [[SecondViewController alloc]init];

    //使用导航栏控制器切换页面

//    [self.navigationController presentViewController:svc animated:YES completion:nil];

    //push入栈 将当前的界面入栈，这个界面消失，将新的界面推送出来

    //pop 将当前的界面消失，从栈上最上面的界面（最后一个界面）出栈

    //设置默认提供的返回按钮的标题

    UIBarButtonItem *backItem = [[UIBarButtonItem alloc]initWithTitle:@"返回" style:UIBarButtonItemStyleDone target:nil action:nil];

    self.navigationItem.backBarButtonItem = backItem;  

    [self.navigationController showViewController:svc sender:self];

}

-(void)viewWillAppear:(BOOL)animated{

    [super viewWillAppear:animated];

    //显示工具栏

    self.navigationController.toolbarHidden = NO;

    self.navigationController.toolbar.barTintColor = [UIColor greenColor];

    //默认工具栏高44，导航栏高44

    //可以隐藏导航栏

//    self.navigationController.navigationBarHidden = YES;

}

 SecondViewController类.m

-(void)viewDidLoad{

    [super viewDidLoad];

    UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];

    [btn setTitle:@"back" forState:UIControlStateNormal];

    btn.frame = CGRectMake(100, 200, 120, 50);

    [btn addTarget:self action:@selector(goback) forControlEvents:UIControlEventTouchUpInside];

    btn.tintColor = [UIColor whiteColor];

    [self.view addSubview:btn];

}

-(void)goback{

     //present 在现有的界面上盖上一层，dismissViewController删除

    //如果之前使用 的push 那么用pop

    [self.navigationController popViewControllerAnimated:YES];

    [self dismissViewControllerAnimated:YES completion:nil];

}

拓：navigationbar 上加多个button：

UIView *rightBarView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 60, 31)];
    
    UIButton *phonebutton = [UIButton buttonWithType:UIButtonTypeCustom];
    phonebutton.frame=CGRectMake(0, 5, 25, 25);
    [phonebutton setImage:[UIImage imageNamed:@"phone.png"] forState:UIControlStateNormal];
    [phonebutton addTarget:self action:@selector(phoneclick)forControlEvents:UIControlEventTouchDown];
    [rightBarView addSubview:phonebutton];
    
    UIButton *mapbutton = [UIButton buttonWithType:UIButtonTypeCustom];
    [mapbutton setFrame:CGRectMake(30, 5, 25, 25)];
    [mapbutton setImage:[UIImage imageNamed:@"c_address.png"] forState:UIControlStateNormal];
    [mapbutton addTarget:self action:@selector(mapclick)forControlEvents:UIControlEventTouchDown];
    [rightBarView addSubview:phonebutton];
    [rightBarView addSubview:mapbutton];
    rightBarView.backgroundColor=[UIColor clearColor];
    
    UIBarButtonItem *rightBtn = [[UIBarButtonItem alloc]initWithCustomView:rightBarView];
    self.navigationItem.rightBarButtonItem = rightBtn;

 更简便的方法：