Question

在样式菜单中实现了带幻灯片的应用程序

目前我有以下设置： ECSlidingViewController的初始View Controller子类。这将处理顶视图控制器（屏幕上显示的主视图）和underLeftController（菜单）的推送。

当单击一行时，菜单是一个tableview控制器子类，新的顶视图控制器被压入堆栈。

每previous question我使用一个导航控制器（子类），它包含一个根视图控制器。每次选择一行时，导航控制器的新实例都会加载一个不同的视图控制器，旧的dealloc'd。例如：

// Check if the settings view is currently displayed if it is just reset the top view else load it to the topviewcontroller.
                UINavigationController *navController = (UINavigationController *)self.slidingViewController.topViewController;
                UIViewController *VC = navController.topViewController;
                if ([VC isKindOfClass:[MESSettingsViewController class]]) {
                    [self.slidingViewController resetTopView];
                } else {
                    MESMainNavViewController *mainNavController = [[MESMainNavViewController alloc] initWithRootViewController:[self.storyboard instantiateViewControllerWithIdentifier:@"SettingsVC"]];

                    __weak typeof(self) weakSelf = self;

                    [self.slidingViewController anchorTopViewOffScreenTo:ECRight animations:nil onComplete:^{
                        CGRect frame = self.slidingViewController.topViewController.view.frame;
                        self.slidingViewController.topViewController = mainNavController;
                        self.slidingViewController.topViewController.view.frame = frame;
                        [weakSelf.slidingViewController resetTopViewWithAnimations:nil onComplete:^{
                            [weakSelf updateCurrentCell];
                        }];
                    }];
                }

此刻一切正常。我遇到的问题是登录序列。如果用户注销，则以模态方式推送不同的导航堆栈。用户完成登录后，会发出通知。这是由初始视图控制器（从上面）接收的：

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didLoginUser) name:@"LoginCompleteNotification" object:nil];

该方法然后处理将用户推送到有问题的子类导航控制器的新实例，以家庭控制器为根。

// If the view controller is not home send them to home
UINavigationController *navController = (UINavigationController *)self.topViewController;
UIViewController *VC = navController.topViewController;
if (![VC isKindOfClass:[MESHomeViewController class]]) {
    UIStoryboard *storyboard;

    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {
        storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard_iPhone" bundle:nil];
    } else if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
        storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard_iPad" bundle:nil];
    }

    MESMainNavViewController *mainNavController = [[MESMainNavViewController alloc] initWithRootViewController:[self.storyboard instantiateViewControllerWithIdentifier:@"HomeVC"]];

    self.topViewController = mainNavController;
    [self resetTopView];

}

问题似乎与以下部分有关：

MESMainNavViewController *mainNavController = [[MESMainNavViewController alloc] initWithRootViewController:[self.storyboard instantiateViewControllerWithIdentifier:@"HomeVC"]];

self.topViewController = mainNavController;

创建导航控制器的这个新实例时，似乎没有调用委托方法willShowViewController？我无法找出原因，它通过菜单表视图更改控制器时调用它，它使用相同的方法创建，任何想法？

Answer 1

苹果医生声明

UINavigationControllerDelegate协议定义方法a 导航控制器委托可以实现改变行为当视图控制器从a的堆栈中被推出和弹出时导航控制器。

因此，我认为仅当您将视图控制器推入或导出导航堆栈时，才会调用方法willShowViewController。

UINavigationController子类在预期时不调用willShowViewController

1 个答案: