如何从Tabbar控制器获取导航控制器并推送特定视图

Question

我正在尝试实施didReceiveRemoteNotification方法。当我收到推送通知时，我想显示一个特定的视图。我的应用使用UITabbarController作为根视图控制器，UINavigationController作为其子级：

这是我的appdelegate：

 - (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo {
        UINavigationController *navController = (UINavigationController *)[[((UITabBarController *)self.window.rootViewController) viewControllers] objectAtIndex:2];
        NSString * storyboardName = @"others";
        UIStoryboard *storyboard = [UIStoryboard storyboardWithName:storyboardName bundle: nil];
        UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"BusinessAccountView"];
        [navController pushViewController:vc animated:YES];
        [PFPush handlePush:userInfo];
}

不幸的是，代码不起作用。如果我将[navController pushViewController:vc animated:YES]更改为[navController presentViewController:vc animated:YES]，它会有效，但我会丢失导航栏。 有没有人知道如何做到这一点？

Answer 1

按照本教程（故事板教程：创建标签栏控制器和Web视图）....

http://www.appcoda.com/storyboard-tutorial-create-tab-bar-controller-and-web-view/

Answer 2

这是一个逐步的解决方案。

• 首先检查是否已选择要推送视图控制器的选项卡。如果没有，请先使用setSelectedIndex或setSelectedViewController选择该标签。
• 接下来，获取tabBarController所选视图控制器的rootViewController（您的UINavigationController）。
• 接下来，实例化您想要推送的viewController，并将其推送到navController。

示例代码：

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo {

    UITabBarController* tabController = self.window.rootViewController;
    if (tabController.selectedIndex != 2) [tabController setSelectedIndex:2];



    UINavigationController *navController = tabController.selectedViewController;
    NSString * storyboardName = @"others";
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:storyboardName bundle: nil];
    UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"BusinessAccountView"];
    [navController pushViewController:vc animated:YES];
    [PFPush handlePush:userInfo];
}