ios开发——标签导航（IB实现和代码实现）

用IB实现标签导航不用写一个代码

1.用Tabbed Application模版新建一个工程；

2.添加View Controller

3.按住control键，从Tab Bar Controller Scene拖一个线到新建的View Controller，在跳出的选项框中选择view controllers

4.修改标签图文，要为不同的设备准备不同的图标：
普通显示屏——无后缀

Retina显示屏——@2x

iphone Plus Retina显示屏——@3x

5.界面布局

6.删各页面对应的类，然后再自己建，全部继承自UIViewController

---

代码实现

@implementation AppDelegate


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    //新建窗口并设置其大小
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen]bounds]];
    //使被使用对象的主窗口显示到屏幕的最前端
    [self.window makeKeyAndVisible];
    //新建UITabBarController类控制器,并设置其为根视图控制器
    UITabBarController *tabBarController = [[UITabBarController alloc] init];
    self.window.rootViewController = tabBarController;
    
    UIViewController *viewController1 = [[HeiViewController alloc]initWithNibName:@"HeiViewController" bundle:nil];
    UIViewController *viewController2 = [[JiViewController alloc]initWithNibName:@"JiViewController" bundle:nil];
    UIViewController *viewController3 = [[LiaoViewController alloc]initWithNibName:@"LiaoViewController" bundle:nil];
    
    tabBarController.viewControllers = @[viewController1,viewController2,viewController3];
    
    return YES;
}

-(id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        self.title = @"黑龙江";
        self.tabBarItem.image = [UIImage imageNamed:@"Hei"];
    }
}