iOS Dev (12) UIView, UIImage, UILabel

#import <UIKit/UIKit.h>

@class ViewController;
@interface AppDelegate: UIResponder<UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) ViewController;

@end

#import "AppDelegate.h"
#import "ViewController.h"

@implementation AppDelegate

- (BOOL) application: (UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    ViewController *viewController = [[ViewController alloc] initWithNibName:nil bundle:nil];
    self.window.rootViewController = viewController;
    [self.window makeKeyAndVisible];

    return YES;
}

- (void) applicationWillResignActive: (UIApplication *)application
{
}

- (void) applicationDidEnterBackground: (UIApplication *)application
{
}

- (void) applicationWillEntreForeground: (UIApplication *)application
{
}

- (void) applicationDidBecomeActive: (UIApplication *)application
{
}

- (void) applicationWillTerminate: (UIApplication *)application
{
}

@end

#import <UIKit/UIKit.h>

@interface ViewController: UIViewController

@end

#import "ViewController.h"

@interface ViewController ()
@end

@implementation ViewController

- (void) viewDidLoad
{
    [super viewDidLoad];

    self.view.backgroundColor = [UIColor redColor];

    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(10, 10, 200, 100)];
    view.backgroundColor = [UIColor colorWithRed:1.0 green:0 blue:0 alpha:0.6];
    [self.view addSubView:view];

    UIImage *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 210, 200, 100)];
    imageView.backgroundColor = [UIColor colorWithRed:0 green:1.0 blue:0 alpha:0.6];
    [self.view addSubView:imageView];

    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 220, 200, 100)];
    label.backgroundColor = [UIColor colorWithRed:0 green:1.0 blue:1.0 alpha:0.6];
    [self.view addSubView:label];
}

- (void) didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

@end