以编程方式在两个UIViewControllers之间切换

Question

我有两个xib文件，每个文件都是自己的类，它覆盖了UIViewController类。我在第一个xib文件中有一个按钮，当它被按下时，它应该带我到新的UIViewController。我曾设法在不同的方式，过渡：

UIViewController* secondViewController = [[UIViewController alloc] initWithNibName:@"SecondViewControllerName" bundle:[NSBundle mainBundle]]; 
     [self.view addSubview:secondViewController.view]; 

或

UIViewController* secondViewController = [[UIViewController alloc] initWithNibName:@"SecondViewControllerName" bundle:[NSBundle mainBundle]]; 
     [self.navigationController pushViewController:secondViewController animated:YES]; 

在第二UIViewController的XIB文件我也有一个按钮，应该带我回到最初的UIViewController。但我不知道如何导航回第一个UIViewController。

我想：

[self.navigationController popViewControllerAnimated:YES]; 

导航到第二UIViewController中的第二种方式，但我得到无法识别的选择发送到实例错误。

非常感谢任何形式的帮助。

---

[编辑＃1：添加源代码]

这里的第一视图控制器.m文件的源代码：

#import "ViewController.h" 
#import "SecondViewController.h" 

@interface ViewController() 

@end 

@implementation ViewController 

- (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. 
} 

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation 
{ 
    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); 
} 

- (IBAction)switchToSecondPage:(id)sender 
{ 
    SecondViewController *secondViewController = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil]; 

    [UIView beginAnimations:@"flipping view" context:nil]; 
    [UIView setAnimationDuration:1]; 
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut]; 
    [UIView setAnimationTransition: UIViewAnimationTransitionCurlDown forView:self.view cache:YES]; 

    [self.view addSubview:secondViewController.view]; 

    [UIView commitAnimations]; 

} 

@end 

这里的第二视图控制器.m文件的源代码：

#import "SecondViewController.h" 

@interface SecondViewController() 

@end 

@implementation SecondViewController 

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

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

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

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation 
{ 
    return (interfaceOrientation == UIInterfaceOrientationPortrait); 
} 

- (IBAction)switchToFirstPage:(id)sender 
{ 
    [UIView beginAnimations:@"flipping view" context:nil]; 
    [UIView setAnimationDuration:1]; 
    [UIView setAnimationCurve:UIViewAnimationCurveEaseIn]; 
    [UIView setAnimationTransition: UIViewAnimationTransitionCurlUp forView:self.view.superview cache:YES]; 

    [self.view removeFromSuperview]; 

    [UIView commitAnimations]; 
} 

@end 

这是我的AppDelegate.m文件：

#import "AppDelegate.h" 

#import "ViewController.h" 

@implementation AppDelegate 

@synthesize window = _window; 
@synthesize viewController = _viewController; 

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; 
    // Override point for customization after application launch. 
    self.viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil]; 
    self.window.rootViewController = self.viewController; 
    [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 

整个项目被制作为单一视图应用程序，并针对XCode 4.3中的iOS 5.1。我找到了一个样品项目，它可以完成我遇到的同样的事情。这是该项目的URL：http://www.devx.com/wireless/Article/42476/0/page/2 它只是为较早的iOS版本编写的。有人能够看到我做错了什么，因为我真的没有想法？ PS：在代码中使用此动画或不使用 - 发生同样的问题，所以动画不是问题，我已经检查过。

---

[编辑＃2：添加错误信息]

这里的错误描述。在上回线主要方法，列举如下：

int main(int argc, char *argv[]) 
{ 
    @autoreleasepool { 
     return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class])); 
    } 
} 

我得到这个错误：

Thread 1: EXC_BAD_ACCESS (code=1, address=0xc00000008)

---

[编辑＃3：解]

我想感谢下面是他的解决方案@btype。我发现为什么编辑＃2的代码不起作用。问题是这样做的：

SecondViewController *secondViewController = [[SecondViewController alloc] initWithNibName:@"SecondViewController" bundle:nil]; 

IBAction METHOD里面！看起来像ARC在我的UIViewController一旦到达范围的末端就立刻擦掉了，这就是为什么我获得了有关将消息发送到已发布实例的信息。我在我的ViewController类中创建了SecondViewController专用字段，之后，一切正常。

如果有人认为我的解释是错误的，并且知道真正困扰我的是什么，请随时回答这个问题并纠正我。

Answer 1

编辑代码：

在AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; 
// Override point for customization after application launch. 
ViewController *viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil]; 

UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:viewController]; 
self.window.rootViewController = navController; 
[self.window makeKeyAndVisible]; 
return YES; 
} 

FirstViewController.m

- (IBAction)switchToSecondPage:(id)sender 
{ 
    [self.navigationController pushViewController:secondViewController animated:YES]; 
} 

SeconViewController.m

- (IBAction)switchToFirstPage:(id)sender 
{ 
    [self.navigationController popToRootViewControllerAnimated:YES]; 
} 

这应该帮助。