目标C：如何从我当前的ViewController后面的ViewController获取导航控制器

Question

我有带导航控制器的ViewController 1，我想推送其他一些VC。但我在它上面显示的ViewController 2不在导航控制器层次结构中。在ViewController 2中，我有一些方法可以将其最小化，但我无法在ViewController 1中访问导航控制器以将其他VC推送到那里。我尝试从窗口进行代码：

UITabBarController *mTabBarVC = (UITabBarController *) [UIApplication sharedApplication].keyWindow.rootViewController;
UINavigationController *prevNavigationController = myTabBarVC.selectedViewController.navigationController;

但是我没有成功，我在prevNavigationController中获得了nil。有人能帮助我吗？

Answer 1

Create in ViewController 2.h:

@property UIViewController *parent;

In ViewController 1 pass self:

viewController2.parent = self;

In ViewController 2 you can now get UINavigationController:

UINavigationController *navVC = self.parent.navigationController;

It's the best way, because you can change structure of your view controllers in future and will get a bug.

If ViewController 2 present modally on ViewController 1, you can get VC1 from VC2 in self.presentingViewController property.