从AppDelegate呈现特定的视图控制器

Question

每次我的应用程序变为活动状态时,我都会尝试显示一个视图控制器(密码请求类型视图).输入正确的密码后,它应该从堆栈中弹出.我试图推送的密码视图不是初始视图控制器,因此我无法从AppDelegate的applicationDidBecomeActive访问它.

我也试过从我的MainViewController的ViewWillAppear中推送密码视图,但是当应用程序变为活动状态时它不会被调用; 仅在刷新屏幕时.

在过去的几天里,我一直在研究类似的问题,但我仍然不理解正确的方法.我听说我可能无法以这种方式推送视图,因为在Storyboard或NavigationController连接/初始化/等之前可能会调用applicationDidBecomeActive.

如果有人能够提供推送/展示视图的正确方法,或者在其他地方做这类事情会更好,我会很感激.

解决:我刚刚从故事板中删除了视图并使用了笔尖代替.我用了:

PasscodeUnlockVC *passcodeUnlock = [[PasscodeUnlockVC alloc] initWithNibName:@"PasscodeUnlockVC" bundle:[NSBundle mainBundle]];
[(UINavigationController *)self.window.rootViewController pushViewController:passcodeUnlock animated:NO];

查看层次数据:

(gdb) po [[(id)UIApp keyWindow] recursiveDescription]
<UIWindow: 0x736a4b0; frame = (0 0; 320 480); layer = <UIWindowLayer: 0x7367b40>>
   | <UILayoutContainerView: 0x76977a0; frame = (0 0; 320 480); autoresize = W+H; layer =     <CALayer: 0x769de60>>
   |    | <UINavigationTransitionView: 0x7692110; frame = (0 0; 320 480); clipsToBounds = YES;      autoresize = W+H; layer = <CALayer: 0x769a8c0>>
   |    |    | <UIViewControllerWrapperView: 0x73868d0; frame = (0 64; 320 416); autoresize =  W+H; layer = <CALayer: 0x75510e0>>
   |    |    |    | <UIView: 0x76b93e0; frame = (0 0; 320 416); autoresize = W+H; layer = <CALayer: 0x7386850>>
   |    | <UINavigationBar: 0x73664b0; frame = (0 20; 320 44); clipsToBounds = YES; opaque =  NO; autoresize = W; layer = <CALayer: 0x7366550>>
   |    |    | <UINavigationBarBackground: 0x7360ea0; frame = (0 0; 320 44); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x7366520>> - (null)
   |    |    | <UINavigationItemView: 0x76b95e0; frame = (160 21; 0 0); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x76aa8e0>>
   |    |    | <UINavigationItemButtonView: 0x7550650; frame = (5 7; 73 30); opaque = NO;   userInteractionEnabled = NO; layer = <CALayer: 0x7368b40>>
Current language:  auto; currently objective-c
(gdb) 

Answer 1

我建议您使用applicationWillEnterForeground:，而不是applicationDidBecomeActive:，因为它更适合多任务手势。例如，如果用户双击主页按钮以显示任务栏，然后在不更改应用程序的情况下关闭任务栏，您不希望显示锁定屏幕。

假设您AppDelegate有一个window属性，并且您知道窗口的根视图控制器是一个UINavigationController.

- (void)applicationWillEnterForeground:(UIApplication *)application {
    PasscodeViewController *pvc = [[PasscodeViewController alloc] init];
    [(UINavigationController *)self.window.rootViewController pushViewController:pvc animated:NO];
    // [pvc release]; if not using ARC
}