iOS开发——纯代码界面（UITabBarController，UINavigationController，UIImageView）

一、创建UITabBarController和UINavigationController（标签栏控制器和导航控制器）

创建两个类，FirstViewController和SecondViewController。修改AppDelegate.m中的代码。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];

    //创建tabBarController控制器
    UITabBarController *tabBarController = [[UITabBarController alloc] init];

    //初始化firstView控制器
    FirstViewController *firstView = [[FirstViewController alloc] init];

    //初始化secondView控制器
    SecondViewController *secondView = [[SecondViewController alloc]init];

    //创建导航控制器nav1，显示firstView
    UINavigationController *nav1 = [[UINavigationController alloc] initWithRootViewController:firstView];

    //创建导航控制器nav2，显示secondView
    UINavigationController *nav2 = [[UINavigationController alloc]initWithRootViewController:secondView];

    //给TabBarController控制器添加子控制器nav1
    [tabBarController addChildViewController:nav1];

    //给TabBarController控制器添加子控制器nav2
    [tabBarController addChildViewController:nav2];

    //根控制器设置为TabBarController
    self.window.rootViewController = tabBarController;
    [self.window makeKeyAndVisible];
    return YES;
}

FirstViewController.m中

- (void)viewDidLoad {
    [super viewDidLoad];

    //设置背景颜色为黄色
    self.view.backgroundColor = [UIColor yellowColor];

}

SecondViewController.m中

- (void)viewDidLoad {
    [super viewDidLoad];

    //设置背景颜色为蓝色
    self.view.backgroundColor = [UIColor blueColor];
}

运行代码，效果图如下

二、创建UIImageView
我在FirstViewController.m中创建一个UIImageView

- (void)viewDidLoad {
    [super viewDidLoad];

    //设置背景颜色为黄色
    self.view.backgroundColor = [UIColor yellowColor];
    UIImage *image = [UIImage imageNamed:@"Totoro副本"];

    //初始化imageView把image设置为它的图片
    UIImageView *imageView = [[UIImageView alloc] initWithImage:image];

    //设置imageView的frame
    imageView.frame = CGRectMake(50, 150, 280, 200);

    //把imageView添加到View上
    [self.view addSubview:imageView];
}

运行代码，效果如下