Programatically Switching Views in Cocoa Touch

[[self parentViewController] dismissModalViewControllerAnimated:YES];

@interface BaseView : UIView {}
@property (nonatomic, assign) UIViewController *parentViewController;
@end

@implementation BaseView
@synthesize parentViewController;

- (id)initWithFrame:(CGRect)frame {
    if ((self = [super initWithFrame:frame])) {
        // Initialization code
    }
    return self;
}

- (void)dealloc {
    [self setParentViewController:nil];
    [super dealloc];
}

@end

@implementation FirstView

- (id)initWithFrame:(CGRect)frame {
    if ((self = [super initWithFrame:frame])) {
        [self setBackgroundColor:[UIColor yellowColor]];

        UIButton *button1 = [[UIButton alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 200.0f, 30.0f)];
        [button1 setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
        [button1 setBackgroundColor:[UIColor whiteColor]];
        [button1 setCenter:CGPointMake(160.0f, 360.0f)];
        [button1 setTitle:@"Show Second View" forState:UIControlStateNormal];
        [button1 addTarget:self action:@selector(switchView:) forControlEvents:UIControlEventTouchUpInside];
        [self addSubview:button1];
        [button1 release];

        UIButton *button2 = [[UIButton alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 200.0f, 30.0f)];
        [button2 setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
        [button2 setBackgroundColor:[UIColor whiteColor]];
        [button2 setCenter:CGPointMake(160.0f, 120.0f)];
        [button2 setTitle:@"Show Sub View" forState:UIControlStateNormal];
        [button2 addTarget:self action:@selector(showView:) forControlEvents:UIControlEventTouchUpInside];
        [self addSubview:button2];
        [button2 release];
    }

    return self;
}

- (void)showView:(id)sender {
    if (viewController == nil) {
        viewController = [[SubViewController alloc] initWithNibName:nil bundle:nil];
    }

    [self addSubview:viewController.view];
}

- (void)switchView:(id)sender {
    SecondView *secondView = [[SecondView alloc] initWithFrame:self.frame];
    [self.parentViewController performSelector:@selector(switchView:) withObject:secondView];
    [secondView release];
}

- (void)dealloc {
    [viewController release];
    [super dealloc];
}

@end

@implementation ViewController

- (void)loadView {
    FirstView *firstView = [[FirstView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 320.0f, 480.0f)];
    [firstView setParentViewController:self];
    [self setView:firstView];
    [firstView release];
}

- (void)switchView:(BaseView *)newView {
    [newView setParentViewController:self];
    [self retain];
    [self setView:newView];
    [self release];
}

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

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

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

@end