iphone - iPhone 上收到本地通知时显示 View Controller 时出现问题

Question

以下代码是我在应用程序收到特定本地通知时显示 View Controller 的最新尝试:

- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification{
    NSLog(@"Notification Received.  UserInfo: %@", [notification.userInfo valueForKey:@"notificationType"]);
    if ([[notification.userInfo valueForKey:@"notificationType"] isEqualToString:@"backup"])
    {
        NSLog(@"Backup notification received.");
        NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
        [defaults setObject:@"Yes" forKey:@"shouldBackup"];
        [defaults synchronize];
        SettingsViewController *vc = [self.window.rootViewController.tabBarController.viewControllers objectAtIndex:3];
        [self.window.rootViewController.tabBarController.navigationController pushViewController:vc animated:NO];
    }
    else
    {
        NSLog(@"Did receive notification: %@, set for date:%@ .", notification.alertBody, notification.fireDate);
    }
}

然后我在 viewDidAppear 方法中使用这段代码来确定是否执行备份:

if ([[defaults objectForKey:@"shouldBackup"] isEqualToString:@"Yes"]){
        [defaults setObject:@"No" forKey:@"shouldBackup"];
        [defaults synchronize];

        HUD = [[MBProgressHUD alloc] initWithView:self.navigationController.view];
        [self.navigationController.view addSubview:HUD];

        HUD.delegate = self;
        HUD.labelText = @"Backing Up Your Data..";
        HUD.minSize = CGSizeMake(135.f, 135.f);

        [HUD showWhileExecuting:@selector(performBackup) onTarget:self withObject:nil animated:YES];
    }

但是，似乎 viewDidAppear 从未被调用，任何人都可以解释我做错了什么吗？我现在尝试了几种不同的方法，但似乎无法让它发挥作用。

谢谢，

泰氨酸

Answer 1

您需要将 SettingsViewController 从 NavigationController 插入堆栈，以便调用其委托(delegate)方法(在本例中为 viewDidAppear)。看来您的 Root View Controller 是 TabBarController。在这种情况下，将 UINavigationControllerDelegate 添加到您的根 VC，有关下一步操作的更多信息可以在此处找到 http://www.touchthatfruit.com/viewwillappear-and-viewdidappear-not-being-ca

此外，您确定 viewDidAppear 没有被调用，还是只是其中的代码没有被调用？添加断点来查找。

最后，你有 [super viewDidAppear:animated];在SettingsViewController的viewDidAppear方法中？

如果所有其他方法都失败，您可以随时从父 View Controller 手动调用 viewDidAppear :)

希望这对您有所帮助!