Modal Window

ModalViewController

static CGFloat kHeight = 480;

@implementation ModalViewController {
    UIView *_bg;
    UIView *_container;
}

- (instancetype)init {
    if (self = [super init]) {
        self.providesPresentationContextTransitionStyle = YES;
        self.definesPresentationContext = YES;
        self.modalPresentationStyle = UIModalPresentationOverCurrentContext;
    }
    return self;
}

- (void)viewDidLoad {
    [super viewDidLoad];

    _bg = [[UIView alloc] initWithFrame:self.view.bounds];
    _bg.backgroundColor = [UIColor clearColor];
    [_bg addGestureRecognizer:[[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(close)]];
    [self.view addSubview:_bg];
    
    _container = [[UIView alloc] initWithFrame:CGRectMake(20, self.view.frame.size.height / 2, self.view.frame.size.width - 40, 0)];
    _container.backgroundColor = [UIColor whiteColor];
    _container.layer.cornerRadius = 6;
    _container.clipsToBounds = YES;
    [self.view addSubview:_container];
}

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    
    [UIView animateWithDuration:0.3 animations:^{
        _bg.backgroundColor = [UIColor colorWithWhite:0.0 alpha:0.7];
        CGRect f = _container.frame;
        f.origin.y = self.view.frame.size.height / 2 - kHeight / 2;
        f.size.height = kHeight;
        _container.frame = f;
    }];
}

- (void)close {
    [UIView animateWithDuration:0.3 animations:^{
        _bg.backgroundColor = [UIColor clearColor];
        CGRect f = _container.frame;
        f.origin.y = self.view.frame.size.height;
        _container.frame = f;
    } completion:^(BOOL finished) {
       [self dismissViewControllerAnimated:NO completion:nil];
    }];
}