我的應用正在終止此錯誤。有任何想法嗎？

Question

2012-05-08 21:33:34.279 Passwordapp[384:fb03] Setting up a Fetched Results Controller for the Entity named Role 
2012-05-08 21:33:34.292 Passwordapp[384:fb03] There's stuff in the database so skipping the import of default data 
2012-05-08 21:33:34.293 Passwordapp[384:fb03] -[LoginViewController viewControllers]: unrecognized selector sent to instance 0x8e7d750 
2012-05-08 21:33:34.301 Passwordapp[384:fb03] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[LoginViewController viewControllers]: unrecognized selector sent to instance 0x8e7d750' 
*** First throw call stack: 
(0x1359022 0x1742cd6 0x135acbd 0x12bfed0 0x12bfcb2 0x2db6 0x390386 0x391274 0x3a0183 0x3a0c38 0x394634 0x1f93ef5 0x132d195 0x1291ff2 0x12908da 0x128fd84 0x128fc9b 0x390c65 0x392626 0x25cd 0x2535) 
terminate called throwing an exception(lldb) 


#import <UIKit/UIKit.h> 
#import "passconst.h" 

@interface LoginViewController : UIViewController <UITextFieldDelegate> 

@property (nonatomic) BOOL pinValidated; 

@end 



#import "LoginViewController.h" 
#import "KeychainWrapper.h" 

@implementation LoginViewController 
@synthesize pinValidated; 

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

- (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. 
} 

// Helper method to congregate the Name and PIN fields for validation. 
- (BOOL)credentialsValidated 
{ 
    NSString *name = [[NSUserDefaults standardUserDefaults] stringForKey:USERNAME]; 
    BOOL pin = [[NSUserDefaults standardUserDefaults] boolForKey:PIN_SAVED]; 
    if (name && pin) { 
     return YES; 
    } else { 
     return NO; 
    } 
} 

- (void)presentAlertViewForPassword 
{ 

    // 1 
    BOOL hasPin = [[NSUserDefaults standardUserDefaults] boolForKey:PIN_SAVED]; 

    // 2 
    if (hasPin) { 
     // 3 
     NSString *user = [[NSUserDefaults standardUserDefaults] stringForKey:USERNAME]; 
     NSString *message = [NSString stringWithFormat:@"What is %@'s password?", user]; 
     UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Enter Password" 
                 message:message 
                 delegate:self 
               cancelButtonTitle:@"Cancel" 
               otherButtonTitles:@"Done", nil]; 
     // 4 
     [alert setAlertViewStyle:UIAlertViewStyleSecureTextInput]; // Gives us the password field 
     alert.tag = kAlertTypePIN; 
     // 5 
     UITextField *pinField = [alert textFieldAtIndex:0]; 
     pinField.delegate = self; 
     pinField.autocapitalizationType = UITextAutocapitalizationTypeWords; 
     pinField.tag = kTextFieldPIN; 
     [alert show]; 
    } else { 
     UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Setup Credentials" 
                 message:@"Secure your Password list!" 
                 delegate:self 
               cancelButtonTitle:@"Cancel" 
               otherButtonTitles:@"Done", nil]; 
     // 6 
     [alert setAlertViewStyle:UIAlertViewStyleLoginAndPasswordInput]; 
     alert.tag = kAlertTypeSetup; 
     UITextField *nameField = [alert textFieldAtIndex:0]; 
     nameField.autocapitalizationType = UITextAutocapitalizationTypeWords; 
     nameField.placeholder = @"Name"; // Replace the standard placeholder text with something more applicable 
     nameField.delegate = self; 
     nameField.tag = kTextFieldName; 
     UITextField *passwordField = [alert textFieldAtIndex:1]; // Capture the Password text field since there are 2 fields 
     passwordField.delegate = self; 
     passwordField.tag = kTextFieldPassword; 
     [alert show]; 
    } 
} 

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex 
{ 
    if (alertView.tag == kAlertTypePIN) { 
     if (buttonIndex == 1 && self.pinValidated) { // User selected "Done" 
      [self performSegueWithIdentifier:@"Loginsegue" sender:self]; 
      self.pinValidated = NO; 
     } else { // User selected "Cancel" 
      [self presentAlertViewForPassword]; 
     } 
    } else if (alertView.tag == kAlertTypeSetup) { 
     if (buttonIndex == 1 && [self credentialsValidated]) { // User selected "Done" 
      [self performSegueWithIdentifier:@"Loginsegue" sender:self]; 
     } else { // User selected "Cancel" 
      [self presentAlertViewForPassword]; 
     } 
    } 
} 


#pragma mark - Text Field + Alert View Methods 
- (void)textFieldDidEndEditing:(UITextField *)textField 
{ 
    // 1 
    switch (textField.tag) { 
     case kTextFieldPIN: // We go here if this is the 2nd+ time used (we've already set a PIN at Setup). 
      NSLog(@"User entered PIN to validate"); 
      if ([textField.text length] > 0) { 
       // 2 
       NSUInteger fieldHash = [textField.text hash]; // Get the hash of the entered PIN, minimize contact with the real password 
       // 3 
       if ([KeychainWrapper compareKeychainValueForMatchingPIN:fieldHash]) { // Compare them 
        NSLog(@"** User Authenticated!!"); 
        self.pinValidated = YES; 
       } else { 
        NSLog(@"** Wrong Password :("); 
        self.pinValidated = NO; 
       } 
      } 
      break; 
     case kTextFieldName: // 1st part of the Setup flow. 
      NSLog(@"User entered name"); 
      if ([textField.text length] > 0) { 
       [[NSUserDefaults standardUserDefaults] setValue:textField.text forKey:USERNAME]; 
       [[NSUserDefaults standardUserDefaults] synchronize]; 
      } 
      break; 
     case kTextFieldPassword: // 2nd half of the Setup flow. 
      NSLog(@"User entered PIN"); 
      if ([textField.text length] > 0) { 
       NSUInteger fieldHash = [textField.text hash]; 
       // 4 
       NSString *fieldString = [KeychainWrapper securedSHA256DigestHashForPIN:fieldHash]; 
       NSLog(@"** Password Hash - %@", fieldString); 
       // Save PIN hash to the keychain (NEVER store the direct PIN) 
       if ([KeychainWrapper createKeychainValue:fieldString forIdentifier:PIN_SAVED]) { 
        [[NSUserDefaults standardUserDefaults] setBool:YES forKey:PIN_SAVED]; 
        [[NSUserDefaults standardUserDefaults] synchronize]; 
        NSLog(@"** Key saved successfully to Keychain!!"); 
       }     
      } 
      break; 
     default: 
      break; 
    } 
} 

#pragma mark - View lifecycle 

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    self.pinValidated = NO; 
} 

- (void)viewDidAppear:(BOOL)animated 
{ 
    [super viewDidAppear:animated]; 
    [self presentAlertViewForPassword]; 
    [super viewDidAppear:animated]; 

    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil]; 
    UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"LoginViewController"]; 
    [vc setModalPresentationStyle:UIModalPresentationFullScreen]; 

    [self presentModalViewController:vc animated:YES]; 
} 

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

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation 
{ 
    // Return YES for supported orientations 
    return (interfaceOrientation == UIInterfaceOrientationPortrait); 
} 

@end 

Answer 1

你正試圖調用你的項目[loginViewControllerObject viewController];這是一個導航控制器方法