Question

假设，在Xcode上的我的xiphone项目中，我有一个闪屏“a”，第一个视图“b”，第二个视图“c”，第二个视图上的“后退”按钮。现在我的任务是，当我的应用程序第一次启动时，将启动启动画面。然后会显示“b”。然后转到“c”。之后，我将再次启动应用程序，将显示视图“c”。如果我想看到视图“b”，我必须在视图“c”上按“后退”按钮。否则视图“b”将永远不会显示。

这是我的问题。我怎么能解决这个问题？

Answer 1

您可以使用通知。因此，在视图控制器C中，您可以：

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

    // add notification to be informed if the app becomes active while
    // this view controller is active, and if so, to invoke the
    // appDidBecomeActive method.

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appDidBecomeActive)
                                                 name:UIApplicationDidBecomeActiveNotification
                                               object:nil];
}

- (void)appDidBecomeActive
{
    // do whatever you want in this method. for example, if you did
    // a modal segue (or presentViewController) to present this
    // view controller's view, then you'd dismiss like thus:

    [self dismissViewControllerAnimated:NO completion:nil];
}

- (void)viewWillDisappear:(BOOL)animated
{
    // when this view disappears, we should remove the observer on
    // the UIApplicationDidBecomeActiveNotification

    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:UIApplicationDidBecomeActiveNotification
                                                  object:nil];
}

如何管理iPhone中的视图导航？

1 个答案: