从SKScene呈现UIViewController

Question

我试图从SKScene呈现一个UIViewController,但应用程序崩溃,这是我的代码:

1-:

 UIViewController *vc = self.view.window.rootViewController;
    helpVC = [[HelpViewController alloc]initWithNibName:@"HelpViewController" bundle:nil];
    [vc presentViewController: helpVC animated: YES completion:nil];

2-

   helpVC = [[HelpViewController alloc]initWithNibName:@"HelpViewController" bundle:nil];
    SKScene *sks = (SKScene*)helpVC;
    [self.view presentScene:sks];

在这两种方式我的应用程序崩溃,谢谢你的帮助

崩溃的原因是:

2014-02-08 16:38:29.119 BrickRacer[13883:70b] -[UIView presentScene:]: unrecognized selector sent to instance 0x10bb7ea50
2014-02-08 16:38:29.122 BrickRacer[13883:70b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIView presentScene:]: unrecognized selector sent to instance 0x10bb7ea50'
*** First throw call stack:
(
    0   CoreFoundation                      0x0000000101fe8795 __exceptionPreprocess + 165
    1   libobjc.A.dylib                     0x0000000101d4b991 objc_exception_throw + 43
    2   CoreFoundation                      0x0000000102079bad -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
    3   CoreFoundation                      0x0000000101fda09d ___forwarding___ + 973
    4   CoreFoundation                      0x0000000101fd9c48 _CF_forwarding_prep_0 + 120
    5   BrickRacer                          0x000000010000bb6d -[ViewController viewDidLoad] + 317
    6   BrickRacer                          0x000000010000b996 -[HelpViewController viewDidLoad] + 54
    7   UIKit                               0x0000000100971fe4 -[UIViewController loadViewIfRequired] + 562
    8   UIKit                               0x00000001009721bd -[UIViewController view] + 29
    9   UIKit                               0x000000010097f03f -[UIViewController viewControllerForRotation] + 54
    10  UIKit                               0x0000000100977f5f -[UIViewController _visibleView] + 87
    11  UIKit                               0x0000000100bb7f89 -[UIWindowController transition:fromViewController:toViewController:target:didEndSelector:animation:] + 4550
    12  UIKit                               0x000000010097c579 -[UIViewController presentViewController:withTransition:completion:] + 4769
    13  BrickRacer                          0x000000010001c6a9 -[Menu help] + 521
    14  BrickRacer                          0x000000010001c43a -[Menu touchesBegan:withEvent:] + 554
    15  SpriteKit                           0x00000001017d8712 -[SKView touchesBegan:withEvent:] + 611
    16  UIKit                               0x00000001008bba84 -[UIWindow _sendTouchesForEvent:] + 300
    17  UIKit                               0x00000001008bc633 -[UIWindow sendEvent:] + 988
    18  UIKit                               0x0000000100895fa2 -[UIApplication sendEvent:] + 211
    19  UIKit                               0x0000000100883d7f _UIApplicationHandleEventQueue + 9549
    20  CoreFoundation                      0x0000000101f77ec1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
    21  CoreFoundation                      0x0000000101f77792 __CFRunLoopDoSources0 + 242
    22  CoreFoundation                      0x0000000101f9361f __CFRunLoopRun + 767
    23  CoreFoundation                      0x0000000101f92f33 CFRunLoopRunSpecific + 467
    24  GraphicsServices                    0x0000000102abe3a0 GSEventRunModal + 161
    25  UIKit                               0x0000000100886043 UIApplicationMain + 1010
    26  BrickRacer                          0x000000010000ea93 main + 115
    27  libdyld.dylib                       0x0000000104ab15fd start + 1
    28  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) 

Answer 1

不要试图呈现UIViewController从SKScene直接,这打破了MVC模式.SKScene是一部分View,View不应该知道任何事情ViewController.

相反,你可以用NSNotificationCenter通知SKScene的UIViewController,它应该提供了另一种UIViewController:

在SKScene's UIViewController:

- (void)awakeFromNib {
    [[NSNotificationCenter defaultCenter] 
        addObserver:self
        selector:@selector(goToGameOverViewController:)
        name:@"GoToGameOverViewController"
        object:nil];
}

.

-(void)goToGameOverViewController:(NSNotification *) notification {
    // Perform a segue or present ViewController directly
    //[self performSegueWithIdentifier:@"GameOverSegue" sender:self];
    HelpViewController *helpVC = [[HelpViewController alloc]initWithNibName:@"HelpViewController" bundle:nil];
    [self presentViewController:helpVC animated: YES completion:nil];
}

.

- (void) dealloc
{
    // If you don't remove yourself as an observer, the Notification Center
    // will continue to try and send notification objects to the deallocated
    // object.
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

在SKScene:

- (void)gameOver {
    [[NSNotificationCenter defaultCenter]
         postNotificationName:@"GoToGameOverViewController" object:self];
}