呼び出しが pushViewController でも presentModalViewController でも対応できるViewController 用のスニペット

ChildController.m

@interface ChildController ()
@property(nonatomic, retain) UINavigationController* navigationController;
@end

@implementation ChildController

@synthesize navigationController;

- (void)viewDidLoad
{
  [super viewDidLoad];
  
  /** 
   * 呼び出しが pushViewController でも presentModalViewController でも対応できるViewController 用のスニペット
   */
  if( !self.navigationController && ![self.parentViewController isKindOfClass:[UINavigationController class]] ){
    /** 親元不明のModalViewController はNavigationBar と閉じるボタンをつけてやる */
    self.navigationController = [[UINavigationController alloc] initWithRootViewController:self];
    UIBarButtonItem* backButton = [[UIBarButtonItem alloc] init];
    backButton.style = UIBarButtonItemStylePlain;
    backButton.title = @"閉じる";
    backButton.target = self;
    backButton.action = @selector(dismissModalViewControllerAnimated:);
    self.navigationItem.rightBarButtonItem = backButton;
    
    self.navigationController.view = self.view;
    [self.view addSubview:self.navigationController.navigationBar];
  }
}