Cocoa Touch - iPhone App se bloque lorsque vous appuyez sur le bouton?

Question

Ceci est ma première application. Il ne plante pas le simulateur ne fait que vous ramener à l'écran d'accueil. Ce n'est pas mon premier programme de cacao (je ne suis pas non plus un pro du cacao), juste mon premier iPhone.

Il se bloque lorsque vous appuyez sur le letsPlayButton, qui exécute la méthode -(IBAction)letsPlay:(id)sender;.

Aidez-moi! Je suis tellement perdu avec ce qui ne va pas!

.H

#import <UIKit/UIKit.h> 

@interface BrainiacViewController : UIViewController { 
    IBOutlet UILabel  *theQuestion; 
    IBOutlet UILabel  *theScore; 
    IBOutlet UILabel  *theLives; 
    IBOutlet UIButton *answerOne; 
    IBOutlet UIButton *answerTwo; 
    IBOutlet UIButton *answerThree; 
    IBOutlet UIButton *answerFour; 
    IBOutlet UIButton *letsPlayButton; 
    NSString *questionNumber; 
    NSInteger myScore; 
    NSInteger myLives; 
    NSInteger usersAnswer; 
    NSArray *theQuiz; 

    //quiz dictionarys 
    NSMutableDictionary *question, *rightAnswer, *wrongOne, *wrongTwo, *wrongThree; 
} 

-(IBAction)buttonOne:(id)sender; 
-(IBAction)buttonTwo:(id)sender; 
-(IBAction)buttonThree:(id)sender; 
-(IBAction)buttonFour:(id)sender; 
-(IBAction)letsPlay:(id)sender; 

-(void)checkAnswer; 

-(void)askQuestion; 

-(void)updateScore; 

-(void)loadQuiz; 
@end 

.M

#import "BrainiacViewController.h" 

@implementation BrainiacViewController 

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

-(IBAction)buttonOne:(id)sender{ 
    usersAnswer = 1; 
} 
-(IBAction)buttonTwo:(id)sender{ 
    usersAnswer = 2; 
} 
-(IBAction)buttonThree:(id)sender{ 
    usersAnswer = 3; 
} 
-(IBAction)buttonFour:(id)sender{ 
    usersAnswer = 4; 
} 
-(IBAction)letsPlay:(id)sender{ 
    //un hide answer buttons 
    [answerOne setHidden:NO]; 
    [answerTwo setHidden:NO]; 
    [answerThree setHidden:NO]; 
    [answerFour setHidden:NO]; 

    //hide the lets play button 
    [letsPlayButton setHidden:YES]; 

    //assign values to variables 
    myScore = 0; 
    myLives = 3; 
    questionNumber = 0; 
    //ask question and start game 
    [self askQuestion]; 
} 


-(void)checkAnswer{ 
    [question objectForKey:questionNumber]; 
    [rightAnswer objectForKey:questionNumber]; 
    [wrongOne objectForKey:questionNumber]; 
    [wrongTwo objectForKey:questionNumber]; 
    [wrongThree objectForKey:questionNumber]; 

} 

-(void)askQuestion{ 
    //create array to mix up the possible answers 
    NSMutableArray *possibleAnswers = [[NSMutableArray alloc] init]; 
    [possibleAnswers addObject:[rightAnswer objectForKey:questionNumber] ]; 
    [possibleAnswers addObject:[wrongOne objectForKey:questionNumber] ]; 
    [possibleAnswers addObject:[wrongTwo objectForKey:questionNumber] ]; 
    [possibleAnswers addObject:[wrongThree objectForKey:questionNumber] ]; 


    //set labels/buttons for question 
    theQuestion.text = [question objectForKey:questionNumber]; 


    //user picks a answer button and sets a value to usersAnswer 
    questionNumber = questionNumber + 1; 
    [self checkAnswer]; 

} 

-(void)updateScore{ 
} 

-(void)loadQuiz{ //assigns dictionary values 
    //*KEY* defines question number 
    [question setObject:@"Which is NOT a starwars movie?" forKey:@"1"]; 
    [rightAnswer setObject:@"Attack of the Jedi" forKey:@"1"]; 
    [wrongOne setObject:@"A New Hope" forKey:@"1"]; 
    [wrongTwo setObject:@"The Phantom Menace" forKey:@"1"]; 
    [wrongThree setObject:@"Attack of the Clones" forKey:@"1"]; 

    [question setObject:@"In what state is the majority of Yellow Stone National Park in?" forKey:@"2"]; 
    [rightAnswer setObject:@"Wyoming" forKey:@"2"]; 
    [wrongOne setObject:@"California" forKey:@"2"]; 
    [wrongTwo setObject:@"Ohio" forKey:@"2"]; 
    [wrongThree setObject:@"Nebraska" forKey:@"2"]; 

    [question setObject:@"In the US, what household pet is the most common?" forKey:@"2"]; 
    [rightAnswer setObject:@"Dogs" forKey:@"2"]; 
    [wrongOne setObject:@"Cats" forKey:@"2"]; 
    [wrongTwo setObject:@"Hamsters" forKey:@"2"]; 
    [wrongThree setObject:@"Komodo Dragons" forKey:@"2"]; 

    [question setObject:@"A plane is traveling 2675 miles every 5 hours. How fast is the plane going in Miles per Hour?" forKey:@"3"]; 
    [rightAnswer setObject:@"535 Mph" forKey:@"3"]; 
    [wrongOne setObject:@"325 Mph" forKey:@"3"]; 
    [wrongTwo setObject:@"535 Mph" forKey:@"3"]; 
    [wrongThree setObject:@"420 Mph" forKey:@"3"]; 
} 
@end 

appdelagate.h

#import <UIKit/UIKit.h> 

@class BrainiacViewController; 

@interface BrainiacAppDelegate : NSObject <UIApplicationDelegate> { 
    UIWindow *window; 
    BrainiacViewController *viewController; 
} 

@property (nonatomic, retain) IBOutlet UIWindow *window; 
@property (nonatomic, retain) IBOutlet BrainiacViewController *viewController; 

@end 

appdelegate.m

#import "BrainiacAppDelegate.h" 
#import "BrainiacViewController.h" 

@implementation BrainiacAppDelegate 

@synthesize window; 
@synthesize viewController; 


#pragma mark - 
#pragma mark Application lifecycle 

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

    // Override point for customization after application launch. 

    // Add the view controller's view to the window and display. 
    [window addSubview:viewController.view]; 
    [window makeKeyAndVisible]; 

    return YES; 
} 


- (void)applicationWillResignActive:(UIApplication *)application { 
    /* 
    Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state. 
    Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game. 
    */ 
} 


- (void)applicationDidEnterBackground:(UIApplication *)application { 
    /* 
    Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later. 
    If your application supports background execution, called instead of applicationWillTerminate: when the user quits. 
    */ 
} 


- (void)applicationWillEnterForeground:(UIApplication *)application { 
    /* 
    Called as part of transition from the background to the inactive state: here you can undo many of the changes made on entering the background. 
    */ 
} 


- (void)applicationDidBecomeActive:(UIApplication *)application { 
    /* 
    Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface. 
    */ 
} 


- (void)applicationWillTerminate:(UIApplication *)application { 
    /* 
    Called when the application is about to terminate. 
    See also applicationDidEnterBackground:. 
    */ 
} 


#pragma mark - 
#pragma mark Memory management 

- (void)applicationDidReceiveMemoryWarning:(UIApplication *)application { 
    /* 
    Free up as much memory as possible by purging cached data objects that can be recreated (or reloaded from disk) later. 
    */ 
} 

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


@end 

Je l'ai encore essayé et vérifié la console et l'erreur était ceci ... Je ne sais pas ce que cela signifie.

[Session started at 2010-07-11 12:24:40 -0400.] 
2010-07-11 12:24:45.729 Brainiac[46764:207] -[NSCFString letsPlay:]: unrecognized selector sent to instance 0x5944f00 
2010-07-11 12:24:45.733 Brainiac[46764:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSCFString letsPlay:]: unrecognized selector sent to instance 0x5944f00' 
*** Call stack at first throw: 
(
    0 CoreFoundation      0x02395919 __exceptionPreprocess + 185 
    1 libobjc.A.dylib      0x024e35de objc_exception_throw + 47 
    2 CoreFoundation      0x0239742b -[NSObject(NSObject) doesNotRecognizeSelector:] + 187 
    3 CoreFoundation      0x02307116 ___forwarding___ + 966 
    4 CoreFoundation      0x02306cd2 _CF_forwarding_prep_0 + 50 
    5 UIKit        0x002b9e14 -[UIApplication sendAction:to:from:forEvent:] + 119 
    6 UIKit        0x003436c8 -[UIControl sendAction:to:forEvent:] + 67 
    7 UIKit        0x00345b4a -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 527 
    8 UIKit        0x003446f7 -[UIControl touchesEnded:withEvent:] + 458 
    9 UIKit        0x002dd2ff -[UIWindow _sendTouchesForEvent:] + 567 
    10 UIKit        0x002bf1ec -[UIApplication sendEvent:] + 447 
    11 UIKit        0x002c3ac4 _UIApplicationHandleEvent + 7495 
    12 GraphicsServices     0x02bfbafa PurpleEventCallback + 1578 
    13 CoreFoundation      0x02376dc4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52 
    14 CoreFoundation      0x022d7737 __CFRunLoopDoSource1 + 215 
    15 CoreFoundation      0x022d49c3 __CFRunLoopRun + 979 
    16 CoreFoundation      0x022d4280 CFRunLoopRunSpecific + 208 
    17 CoreFoundation      0x022d41a1 CFRunLoopRunInMode + 97 
    18 GraphicsServices     0x02bfa2c8 GSEventRunModal + 217 
    19 GraphicsServices     0x02bfa38d GSEventRun + 115 
    20 UIKit        0x002c7b58 UIApplicationMain + 1160 
    21 Brainiac       0x00002790 main + 102 
    22 Brainiac       0x00002721 start + 53 
) 
terminate called after throwing an instance of 'NSException' 

Answer 1

J'ai essayé encore et vérifié la console et l'erreur était ceci ... Je ne sais pas ce que cela signifie.

2010-07-11 12:24:45.729 Brainiac[46764:207] -[NSCFString letsPlay:]: unrecognized selector sent to instance 0x5944f00 

vous a envoyé un message (letsPlay:) à un objet qui ne répond pas à ce message (un NSString, ici comme NSCFString).

Ce genre de chose se produit généralement parce que vous ne l'avez pas bien accrochez à l'objet que vous vouliez dire d'envoyer letsPlay:, donc il a obtenu désallouée. Un NSString plus tard a été alloué à la même adresse, donc tout ce qui maintenait le pointeur sur l'ancien objet (et pense qu'il l'est toujours) maintenant le pointeur sur NSString. Même pointeur, objet différent. Puis, quand un de ces prétendus propriétaires essaie d'envoyer le message à l'objet, il pense qu'il a encore ... boom.

La solution est de vérifier vos propriétés et de vous assurer que vous retenez (ou créez en utilisant alloc et non autoreleasing) ce que vous voulez dire posséder.

Sur une note connexe:

NSMutableArray *possibleAnswers = [[NSMutableArray alloc] init]; 
[possibleAnswers addObject:[rightAnswer objectForKey:questionNumber] ]; 
[possibleAnswers addObject:[wrongOne objectForKey:questionNumber] ]; 
[possibleAnswers addObject:[wrongTwo objectForKey:questionNumber] ]; 
[possibleAnswers addObject:[wrongThree objectForKey:questionNumber] ]; 

Si vous voulez dire pour que cela soit une variable locale, vous devez libérer d'ici la fin de la méthode, ou vous fuira ce tableau. Si vous souhaitez posséder cet objet, vous devez le déplacer vers une variable d'instance et supprimer la variable locale, puis continuer à créer l'objet comme vous le faites actuellement.

Lecture obligatoire: Le Memory Management Programming Guide for Cocoa.

Answer 2

Vous devez 'boîte' l'entier questionNumber dans un objet NSNumber, comme ceci:

theQuestion.text = [question objectForKey:[NSNumber numberWithInt:questionNumber]]; 

Ou, vous pouvez utiliser le plus approprié NSArray indexeur:

theQuestion.text = [question objectAtIndex:questionNumber];