ios - UINavigation Controller 在显示 ViewController 时崩溃

Question

我有一个 UINavigationController，其中有一个带有 UITableView 的 MainViewController 和一个 ToolBar 按钮。选择一个 UITableViewCell 将推送到 SecondViewController，点击工具栏按钮将推送到 ThirdViewController，两者都与 StoryBoard segue。两个 ViewController 都被第一次推送 OK，但是当 UINavigationController 首先推送 SecondViewController 并弹回 MainViewController，然后推送 ThirdViewController 将导致应用程序崩溃。所以我认为 ThirdViewController 的 代码一定有问题，但错误消息是:

SecondViewController respondsToSelector:]: message sent to deallocated instance 0x115621d0

奇怪的是，为什么在我推送 ThirdViewController 时，SecondViewController 出现在错误消息中？我放置了断点，MainViewController 上的 prepareForSegue 被调用时没有错误，ThirdViewController 上的 viewDidLoad 被调用后没有错误错误，但是当我在 viewDidLoad 结束时单击继续时，应用程序崩溃了。在启用 Zombies 的情况下使用 Instruments 显示:

我正在推送 ThirdViewController，为什么代码会进入 SecontViewController segue？我不知道代码有什么问题？我正在使用 ARC，所以我没有错误地发布任何东西。

SB截图:

所有三个 View Controller 的类定义

// MainViewController.h
@interface MainViewController : UITableViewController <UIAlertViewDelegate, UIActionSheetDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate, MFMailComposeViewControllerDelegate, UIPageViewControllerDelegate, UIPageViewControllerDataSource, SecondViewControllerDelegate> {
    BOOL _thumbnailTapped;

}

- (void)showQuickTour:(id)sender;
- (void)Purchased;
- (IBAction) pickThumbnailImage:(id)sender;


@property (strong, nonatomic) UIPageViewController *pageViewController;
@property (strong, nonatomic) NSArray *pageTitles;
@property (strong, nonatomic) NSArray *pageImages;
@property (strong, nonatomic) NSArray *pageImages_3_5;


@property (nonatomic, weak)   IBOutlet UIBarButtonItem *editOptionsLabel;
@property (nonatomic, strong) NSCache* thumbnailCache;
@property (nonatomic, strong) NSCache* emailCountCache;
@property (nonatomic, weak)   NSIndexPath* currentIndexPath;
@property (nonatomic, readwrite) BOOL deleting;
@property (nonatomic, weak)   ABContact *returnedMailingList;
@property (nonatomic, strong) SoundEffect* deleteFX;

@end


//SecondViewController.h
@protocol SecondViewControllerDelegate <NSObject>
- (void)getBackCurrentMailingList:(id)controller didFinishEnteringItem:(ABContact *)currentMailingList;
@end


@protocol ModalViewDelegate
@optional
- (void) getBackGroup:(NSDictionary *) group;
- (void) getBackContacts:(NSArray *)c andEmails:(NSArray *)e;
- (void) getBackPastedContacts:(NSArray *)contacts;
- (void) getBackPullView:(BOOL)pullled;
@end

@interface SecondViewController : UITableViewController <ModalViewDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate, UIActionSheetDelegate, UIAlertViewDelegate, MFMailComposeViewControllerDelegate>
{
    ABContact *currentML;
    BOOL _isViewPulled;
}

- (IBAction) pickImage:(id)sender;
- (IBAction) composeEmail:(id)sender;
- (IBAction) PasteGroup:(id)sender;
- (IBAction) dismissPopUp:(id)sender;

@property (nonatomic, weak)     IBOutlet UIBarButtonItem *composeButton;
@property (nonatomic, strong)   NSCache*                thumbnailCache;
@property (nonatomic, strong)   ABContact*              currentML;
@property (nonatomic, strong)   NSMutableDictionary*    currentMailingList;
@property (nonatomic, strong)   NSArray*                pastedContatcs;
@property (nonatomic, strong)   NSDictionary*           groupDictionary;
@property (nonatomic, readwrite) ABRecordID             currentRecordID;
@property (nonatomic, strong)   UIView*                 fadingView;
@property (nonatomic, strong)   UILabel*                fadingLabel;
@property (nonatomic, strong)   UIActivityIndicatorView* fadingActivityIndicator;
@property (nonatomic, weak)     id <SecondViewControllerDelegate> delegate;
@property (nonatomic, strong)   SoundEffect* deleteFX;

@end


//ThirdViewController.h
@interface SettingsViewController : UIViewController <SKPaymentTransactionObserver, SKProductsRequestDelegate>
{

}

@property (strong, nonatomic) SKProductsRequest *request;
@property (strong, nonatomic) SKProduct *product;
@property (strong, nonatomic) NSString *productID;
@property (weak,   nonatomic) IBOutlet UILabel *versionLabel;
@property (weak,   nonatomic) IBOutlet UILabel *productLabel;
@property (weak,   nonatomic) IBOutlet UITextView *productDescription;
@property (weak,   nonatomic) IBOutlet UIButton *purchaseButton;
@property (weak,   nonatomic) IBOutlet UIButton *buyButton;
@property (weak,   nonatomic) IBOutlet UISwitch *soundFXSwitch;
@property (weak,   nonatomic) IBOutlet UIActivityIndicatorView *loadingIndicator;

- (IBAction)buyProduct:(id)sender;
- (IBAction)restorePurchase:(id)sender;
- (IBAction)switchSoundFX:(id)sender;
- (IBAction)showQuickTour:(id)sender;

-(void)getProductID:(UIViewController *)viewController;

@end

Answer 1

请检查您是否将 secondVC 指定为 UINavigationControllerDelegate？如果是，请尝试在 viewWillDisappear 中将该值设置为 nil