ios - 防止用户通过登录进入 UITabBarController

Question

我有一个登录视图，它指向一个UITabBarController带有四个选项卡的选项卡。我想要的是当密码为空或错误时，提示用户留在同一视图（登录视图）而不是标签栏控制器。换句话说，如果密码正常（非空且正确），我希望能够查看标签栏。是否可以一直显示登录视图，直到提供的密码正确？有任何想法吗？

Answer 1

您所描述的是模态视图控制器。如果您有一个现有的登录控制器，请展示它：

[someViewController presentViewController:loginController animated:YES completion:nil]

这将定位loginController在所有其他控制器之上。当用户输入了正确的密码（并且只有这样！）你应该关闭它：

[self dismissViewControllerAnimated:YES completion:nil];

如果您希望loginController有一个标题栏，请记住将其包装在 a 中UINavigationController并显示导航控制器。

Answer 2

YourAppDelegate.m：

@interface YourAppDelegate()
@property( nonatomic, retain ) UITabBarController *tabBarController;
@property( nonatomic, retain ) UIViewController *loginViewController;
- (void)allocateAndShowLoginViewController;
- (void)allocateAndShowMenuController;
@end
@implementation YourAppDelegate
@synthesize tabBarController;
@synthesize loginViewController;
#pragma mark -
#pragma mark Application lifecycle

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];           
    [self.window makeKeyAndVisible];
    [self allocateAndShowLoginViewController];       
    return YES;
}

- (void)allocateAndShowLoginViewController{
     // Show Login View Controller (for example:)
     // My Sample login view controller uses delegate to report when user has been logged in
     self.loginViewController = [[[UIViewController alloc] initWithDelegate:self] autorelease];
     self.window.rootViewController = loginViewController;
}  

- (void)allocateAndShowTabBarController{
    self.tabBarController = [[[UITabBarController alloc] init] autorelease];

    UINavigationController      *viewController1 = [[[UINavigationController alloc] initWithRootViewController:[[[UIViewController alloc] init] autorelease]] autorelease];

    UINavigationController      *viewController2 = [[[UINavigationController alloc] initWithRootViewController:[[[UIViewController alloc] init] autorelease]] autorelease];

    self.tabBarController.viewControllers = @[viewController1, viewController2];
    self.tabBarController.customizableViewControllers = nil;

    self.window.rootViewController = self.tabBarController;
}


#pragma mark - loginViewControllerDelegate
- (void)loginViewControllerDidLogin:(PSLoginViewController*)controller{
    [self allocateAndShowMenuController];
}

类似的东西

Answer 3

据我了解，您想在某个时间禁用标签栏。

如果你使用UITabBarController你可以使用

- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController {
    return NO; 
}

或者你可以禁用userInteractionEnabled

myTabBar.userInteractionEnabled = NO;

您还可以向您UITabBarController的示例添加一些子视图以淡出您的标签栏

UIView *view = [[UIView alloc] initWithFrame:self.view.bounds];
view.backgroundColor = [UIColor blackColor];
view.alpha = 0.3f;
[self.tabBarController.view addSubview:view];
[view release];