Question

In Xcode 4.2, I know that one can use the storyboard segue to have a push of a button to go to another view.

But say i want to storyboard, but not using segue push, instead code my own button to display another view, how to do it?
Must i include a navigation controller?

EDIT: added source codes

AppDelegate.h

//
//  AppDelegate.h
//  Sandbox1
//
//  Created on 6/29/12.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>
#import "ViewController.h"

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) ViewController *viewController;
@property (nonatomic, retain) UINavigationController *navController;

@end

AppDelegate.m

//
//  AppDelegate.m
//  Sandbox1
//
//  Created on 6/29/12.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//

#import "AppDelegate.h"

@implementation AppDelegate

@synthesize window = _window;
@synthesize viewController;
@synthesize navController;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary     *)launchOptions
{
    // Override point for customization after application launch.

    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.viewController = [[ViewController alloc] initWithNibName:@"ViewController_iPhone"     bundle:nil];
    navController = [[UINavigationController alloc] initWithRootViewController:self.viewController];
    [self.window addSubview:[navController view]];
    [self.window makeKeyAndVisible];

    return YES;
}

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

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

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

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

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

@end

ViewController.h

//
//  ViewController.h
//  Sandbox1
//
//  Created on 6/29/12.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>
#import "CreateViewController.h"

@interface ViewController : UIViewController {
    CreateViewController *createViewController;
}

- (IBAction)clickButton:(id)sender;

@end

ViewController.m

//
//  ViewController.m
//  Sandbox1
//
//  Created on 6/29/12.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//

#import "ViewController.h"

@implementation ViewController

- (IBAction)clickButton:(id)sender{
    if(!createViewController){
        createViewController = [[CreateViewController alloc] initWithNibName:@"CreateViewController" bundle:nil];
    }
    UIBarButtonItem *backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStylePlain target:nil action:nil];
    self.navigationItem.backBarButtonItem = backBarButtonItem;
    [self.navigationController pushViewController:createViewController animated:YES];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Release any cached data, images, etc that aren't in use.
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
}

- (void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}

@end

CreateViewController.h

//
//  CreateViewController.h
//  Sandbox1
//
//  Created bon 6/29/12.
//  Copyright (c) 2012 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface CreateViewController : UIViewController

@end

CreateViewController.m

//
//  CreateViewController.m
//  Sandbox1
//
//

#import "CreateViewController.h"

@implementation CreateViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)didReceiveMemoryWarning
{
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.
}

#pragma mark - View lifecycle

/*
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView
{
}
*/

/*
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad
{
    [super viewDidLoad];
}
*/

- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

@end

Answer 1

I think the button is in FirstViewController. If it is then implement –(IBAction)clickButton and write code and connect it to your bottom in Interface Builder(If you use Interface Builder) . write createViewController object and #import <CreateViewController.h> in FirstViewController.h and you should use UINavigationController.

In FirstViewController.h,

#import "CreateViewController.h"

@interface FirstViewController : UIViewController{

    CreateViewController *createViewController;
}
-(IBAction)clickButton:(id)sender;
@end

In FirstViewController.m, you just add below method

 -(IBAction)clickButton:(id)sender{

if (!createViewController) {
                createViewController = [[CreateViewController alloc] initWithNibName:@"CreateViewController" bundle:nil];

            }

            UIBarButtonItem *backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStylePlain target:nil action:nil];
            self.navigationItem.backBarButtonItem = backBarButtonItem;
            [backBarButtonItem release];
            [self.navigationController pushViewController:createViewController animated:YES];
}

and in AppDelegate.h,

#import "FirstViewController.h"
@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) FirstViewController *viewController;
@property (nonatomic, retain) UINavigationController *navControl;
@end

In AppDelegate.m,

@synthesize window;
@synthesize viewController;
@synthesize navControl;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
    self.viewController = [[[ViewController alloc] initWithNibName:@"ViewController_iPhone" bundle:nil] autorelease];
    navControl = [[UINavigationController alloc] initWithRootViewController:self.viewController];
[self.window addSubview:[navControl view]];
    [self.window makeKeyAndVisible];
    return YES;
}