iphone-将子视图添加到窗口后无法推送模式视图？

Im我的应用程序我有以下代码，第一位在我的应用程序启动时运行，它在模式视图中显示一个登录屏幕。在此之前，我的rootController被添加到了窗口中

模式视图将允许用户登录、查看条款和条件，然后如果用户接受loadMainApp功能，则调用该功能

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Override point for customization after application launch.
    rootController.delegate = self;
    [window addSubview:rootController.view];

    LoginViewController *_loginViewController = [[LoginViewController alloc] initWithNibName:@"LoginView" bundle:[NSBundle mainBundle]];
    self.loginViewController = _loginViewController;
    [_loginViewController release];


    UINavigationController *navi = [[[UINavigationController alloc]initWithRootViewController:loginViewController]autorelease];

    navi.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
    [loginViewController release];
    [rootController presentModalViewController:navi animated:YES];

    [self.window makeKeyAndVisible];
    return YES;
}

当用户接受条款和条件时，调用下一位：

-(void)loadMainApp:(UIView *)fromView{

    [fromView removeFromSuperview];
    [window addSubview:rootController.view];
    rootController.selectedIndex = 2;
    rootController.delegate = self;

}

在这里，我希望能够使用people picker，这是一个模态视图，我尝试使用以下代码：

 ABPeoplePickerNavigationController *picker =
        [[ABPeoplePickerNavigationController alloc]init];
        picker.peoplePickerDelegate = self;

        [rootController presentModalViewController:picker animated:YES];
        [picker release];

但是什么也没有发生，当我试图从我的rootController呈现一个模态视图时，什么也没有显示

这似乎是在ApplicationIDFinishLaunching中的此代码运行后发生的：

LoginViewController *_loginViewController = [[LoginViewController alloc] initWithNibName:@"LoginView" bundle:[NSBundle mainBundle]];
        self.loginViewController = _loginViewController;
        [_loginViewController release];


        UINavigationController *navi = [[[UINavigationController alloc]initWithRootViewController:loginViewController]autorelease];

        navi.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
        [loginViewController release];
        [rootController presentModalViewController:navi animated:YES];

        [self.window makeKeyAndVisible];
        return YES;

如果我根本不显示登录屏幕，而是添加我的rootController

rootController.delegate = self;
        [window addSubview:rootController.view];

在ApplicationIDFinishLaunching函数中，当我显示人员选择器时，一切正常

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是否有一些基本的东西我在这里打破了，或者任何人都能发现我可能做错了什么？

您是否通过

dismissModalViewControllerAnimated:

方法正确地解除了第一个模态视图控制器？如果您只是将模态视图控制器的视图从其superview中删除，那么UIKit可能没有完成大量的文书工作。

您真正应该做的是：

将rootViewController添加到navigationController。然后将navigationController添加到窗口

在rootViewController的viewDidLoad方法中，将loginViewController的委托设置为rootViewController，并将loginViewController的实例显示为模式

完成验收条款后，执行[delegate LoginViewController Finished]

现在在rootViewController中，处理LoginViewController完成方法。这应该包含对[self dismissModalViewControllerAnimated:YES]的调用；关闭登录模式视图。然后您应该以模式视图的形式启动ABPeoplePickerNavigationController

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在AppDelegate中：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    // Make sure rootViewController is initiated by this point.

    UINavigationController *navigationController = [[[UINavigationController alloc] initWithRootViewController:rootViewController] autorelease];

    [window addSubview:rootController.view];
    [self.window makeKeyAndVisible];
    return YES;
}

---

在RootViewController中：

- (void)viewDidLoad {
  [super viewDidLoad];

  LoginViewController *loginViewController = [[[LoginViewController alloc] initWithNibName:@"LoginView" bundle:nil] autorelease];
  loginViewController.delegate = self;

  loginViewController.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
  [self presentModalViewController:loginViewController animated:YES];
}

- (void)loginViewControllerFinished {
  [self dismissModalViewControllerAnimated:YES];

  // Here we are closing one modal. And showing another after that.
  ABPeoplePickerNavigationController *peoplePicker = [[[ABPeoplePickerNavigationController alloc] init] autorelease];
  peoplePicker.peoplePickerDelegate = self;
  [self presentModalViewController:peoplePicker animated:YES];
}

// Make sure LoginViewController has delegate property in header.
// @property (nonatomic, assign) id delegate;
// And put this in implementation (.m) file. @synthesize delegate.
// Don't put release for delegate, since it's not retained. It's only 'assigned'.

- (void)done {
  // Call this when you want to close loginViewController.
  [delegate loginViewControllerFinished];
}

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在LoginViewController中：

- (void)viewDidLoad {
  [super viewDidLoad];

  LoginViewController *loginViewController = [[[LoginViewController alloc] initWithNibName:@"LoginView" bundle:nil] autorelease];
  loginViewController.delegate = self;

  loginViewController.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
  [self presentModalViewController:loginViewController animated:YES];
}

- (void)loginViewControllerFinished {
  [self dismissModalViewControllerAnimated:YES];

  // Here we are closing one modal. And showing another after that.
  ABPeoplePickerNavigationController *peoplePicker = [[[ABPeoplePickerNavigationController alloc] init] autorelease];
  peoplePicker.peoplePickerDelegate = self;
  [self presentModalViewController:peoplePicker animated:YES];
}

// Make sure LoginViewController has delegate property in header.
// @property (nonatomic, assign) id delegate;
// And put this in implementation (.m) file. @synthesize delegate.
// Don't put release for delegate, since it's not retained. It's only 'assigned'.

- (void)done {
  // Call this when you want to close loginViewController.
  [delegate loginViewControllerFinished];
}

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希望这有帮助