实现部分代码关于view的德国国旗实现

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.

    UIView *blackView = [[UIView alloc] initWithFrame:CGRectMake(10, 50, 300, 50)];

    blackView.backgroundColor = [UIColor blackColor];

    [self.view addSubview:blackView];

    UIView *redView = [[UIView alloc] initWithFrame:CGRectMake(10, 100, 300, 50)];

    redView.backgroundColor = [UIColor redColor];

    [self.view addSubview:redView];

    UIView *yellowView = [[UIView alloc] initWithFrame:CGRectMake(10, 150, 300, 50)];

    yellowView.backgroundColor = [UIColor yellowColor];

    [self.view addSubview:yellowView];

}