Question

更新：我在调试中犯了一个错误 - 这个问题不是相关的 - 请参阅下面的评论。

注意：我使用的是自动参考计数

当我的应用开始时 - 我使用UINavigationController在presentViewController:animated:completion内展示了一个视图控制器。该视图控制器将第二个视图控制器加载到导航堆栈。第二个视图控制器使用[self.presentingViewController dismissViewControllerAnimated:YES completion:nil]来解除自身。我的问题是，在第一个视图控制器中都没有调用dealloc和viewDidUnload。但是，使用乐器，我可以看到一旦所呈现的视图控制器被解除，视图控制器就不再被分配。显示第一个视图控制器的代码是

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

    //  check if our context has any accounts                                                                                                                                                                                                
    if( [self.accounts count] == 0 )                                                                                                                                                                                    
    {                                                                                                                                                                                                                                        
        //  Display the Add Account View Controller                                                                                                                                                                                          
        MySettingsViewController *settingsVC = [[MySettingsViewController alloc] initWithNibName:@"MySettingsViewController" bundle:nil];                                                                                                 
        settingsVC.appContext = self.appContext;                                                                                                                                                                                             

        UINavigationController *navVC = [[UINavigationController alloc] initWithRootViewController:settingsVC];                                                                                                                              
        navVC.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;                                                                                                                                                                    

        if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone)                                                                                                                                                      
        {                                                                                                                                                                                                                                    
            //  Display the Add Account View Controller                                                                                                                                                                                      
        }                                                                                                                                                                                                                                    
        else                                                                                                                                                                                                                                 
        {                                                                                                                                                                                                                                    
            navVC.modalPresentationStyle = UIModalPresentationFormSheet;                                                                                                                                                                     
        }                                                                                                                                                                                                                                    

       [self presentViewController:navVC animated:YES completion:nil];                                                                                                                                                                       
    }                                                                                                                                                                                                                                        
}

所以，我没有引用应该坚持的settingsVC，但我不知道为什么我的dealloc没有被调用。任何帮助都会很棒。

Answer 1

由于您未正确释放视图控制器，因此无法调用它们。

您使用settingsVC分配navVC和alloc，从而获得对您必须在以后发布但尚未发布的两个内容的引用。

你可以这样做：

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

    //  check if our context has any accounts                                                                                                                                                                                                
    if( [self.accounts count] == 0 )                                                                                                                                                                                    
    {                                                                                                                                                                                                                                        
        //  Display the Add Account View Controller                                                                                                                                                                                          
        MySettingsViewController *settingsVC = [[MySettingsViewController alloc] initWithNibName:@"MySettingsViewController" bundle:nil];                                                                                                 
        settingsVC.appContext = self.appContext;                                                                                                                                                                                             

        UINavigationController *navVC = [[UINavigationController alloc] initWithRootViewController:settingsVC];
        navVC.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;                                                                                                                                                                    

        // At this points, "settingsVC" is additionally retained by the navigation controller,
        // so we can release it now.
        [settingsVC release];

        if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone)                                                                                                                                                      
        {                                                                                                                                                                                                                                    
            //  Display the Add Account View Controller                                                                                                                                                                                      
        }                                                                                                                                                                                                                                    
        else                                                                                                                                                                                                                                 
        {                                                                                                                                                                                                                                    
            navVC.modalPresentationStyle = UIModalPresentationFormSheet;                                                                                                                                                                     
        }                                                                                                                                                                                                                                    

        [self presentViewController:navVC animated:YES completion:nil];

        // At this point "navVC" is retained by UIKit, so we can release it as well.
        [navVC release];
    }                                                                                                                                                                                                                                        
}

另一种选择就是autorelease。

当被解雇时，UIViewController不会收到dealloc或viewDidUnload

1 个答案: