目錄：
1、利用ViewController中間過渡
2、直接設(shè)置UITabBarController的數(shù)組

比較：相對(duì)來說第2中方式較方便，設(shè)置內(nèi)容、標(biāo)題等比較清晰明確，第1中方式中設(shè)置標(biāo)題等內(nèi)容時(shí)容易搞混，相對(duì)第2中方式?jīng)]有較大的優(yōu)勢(shì)。

1、利用ViewController中間過渡

AppDelegate中代碼設(shè)置

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    
    ViewController *vc = [[ViewController alloc] init];
    self.window.rootViewController = vc;
    
    return YES;
}

ViewController中代碼設(shè)置

    //初始化要使用的三個(gè)VC
    FirstVc *first = [[FirstVc alloc] init];
    SecondVc *second = [[SecondVc alloc] init];
    ThirdVc *third = [[ThirdVc alloc] init];
    
    //初始化三個(gè)nav
    UINavigationController *firstNav = [[UINavigationController alloc] initWithRootViewController:first];
    firstNav.tabBarItem = [[UITabBarItem alloc] initWithTitle:@"111" image:nil tag:1];
    
    UINavigationController *secondNav = [[UINavigationController alloc] initWithRootViewController:second];
    secondNav.tabBarItem = [[UITabBarItem alloc] initWithTitle:@"" image:nil tag:1];

    UINavigationController *thirdNav = [[UINavigationController alloc] initWithRootViewController:third];
    thirdNav.tabBarItem = [[UITabBarItem alloc] initWithTitle:@"333" image:nil tag:1];

    //初始化UITabBarController
    self.tabBarCont = [[UITabBarController alloc] init];
    self.tabBarCont.viewControllers = @[firstNav,secondNav,thirdNav];
    
    self.tabBarCont.selectedIndex = 0;
    self.tabBarCont.delegate = self;
    self.tabBarCont.view.frame = self.view.frame;
    
    [self.view addSubview:self.tabBarCont.view];

各個(gè)VC中的設(shè)置

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.view.backgroundColor = [UIColor whiteColor];
}

- (void)viewWillAppear:(BOOL)animated
{
    self.title = @"first";//此設(shè)置改變nav的標(biāo)題和底部item的標(biāo)題
    self.navigationController.title = @"111";//item標(biāo)題
}

2、直接設(shè)置UITabBarController的數(shù)組

AppDelegate中設(shè)置

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    
    //初始化
    FirstVc *first = [[FirstVc alloc] init];
    SecondVc *second = [[SecondVc alloc] init];
    ThirdVc *third = [[ThirdVc alloc] init];
    
    //創(chuàng)建標(biāo)簽欄控制器
    tabBarControl = [UITabBarController new];
    
    //放入標(biāo)簽欄中
    tabBarControl.viewControllers = @[first,second,third];
    
    //創(chuàng)建導(dǎo)航欄控制器，并指定他的根視圖控制器
    UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:tabBarControl];
    
    //添加中間的按鈕
    //缺點(diǎn)：1、按鈕超過bottom的部分點(diǎn)擊無響應(yīng)    2、點(diǎn)擊除按鈕外的中間部分時(shí)也展示中間item的頁面
    //3個(gè)item是可能范圍太大，如果調(diào)整item數(shù)量，缺點(diǎn)2應(yīng)該影響不大。
    UIButton *btn = [[UIButton alloc] init];
    btn.backgroundColor = [UIColor redColor];
    [btn setFrame:CGRectMake(130, -12, 60, 60)];
    btn.clipsToBounds = YES;
    btn.layer.cornerRadius = 30;
    [btn addTarget:self action:@selector(clickCenterButton) forControlEvents:UIControlEventTouchUpInside];
    
    [tabBarControl.tabBar addSubview:btn];
    
    //指定應(yīng)用的跟視圖控制器
    self.window.rootViewController = nav;
    
    return YES;
}

各個(gè)VC中的設(shè)置

- (instancetype)init
{
    self = [super init];
    
    if (self)
    {
        self.title = @"111";//此處的title是item的標(biāo)題
        
        //設(shè)置圖標(biāo)的默認(rèn)圖片和選中后圖片
        self.tabBarItem.image = [[UIImage imageNamed:@"tabbar_mainframe@2x"]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
        self.tabBarItem.selectedImage = [[UIImage imageNamed:@"tabbar_mainframeHL@2x"]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
        
        //未讀消息數(shù)量（右上角標(biāo)識(shí)）
        [self.tabBarItem setBadgeValue:@"18"];
    }
    
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.view.backgroundColor = [UIColor whiteColor];
}

- (void)viewWillAppear:(BOOL)animated
{
    self.tabBarController.navigationItem.title = @"first";//共同使用一個(gè)navigation，要在此方法中設(shè)置名稱
    
    //設(shè)置右邊導(dǎo)航按鈕
    UIBarButtonItem *rightItem = [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(tapAdd)];

    self.tabBarController.navigationItem.rightBarButtonItem = rightItem;
}

- (void)tapAdd
{
    //此處跳轉(zhuǎn)頁面操作
    //或者彈出頁面
}