在Storyboard中以编程方式访问UIViewController

Question

我正在开发一个具有多个ViewController的应用程序，并且希望从几乎每个UIViewController都可以访问特定的ViewController“登录ViewController”，我知道我可以通过使用从每个控制器到LoginViewController的segue来实现此目的，确保不是最佳解决方案，实现此目的的最佳解决方案是什么？

Answer 1

Use this...variable vc return the viewcontroller you are looking for

  UIStoryboard *aStoryboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:[NSBundle mainBundle]];
  YourViewController *vc = [aStoryboard instantiateViewControllerWithIdentifier:@"YourViewController"];

Answer 2

you can probably do something like this

static LoginViewController *instance; //place in the implementation

- (void) viewDidLoad {
     instance = self;
}

+(LoginViewController *) getInstance { //use this method to access the instance (declare in header)
    return instance;
}

then just import the header where you need to access it and you're done

Answer 3

https://developer.apple.com/library/ios/featuredarticles/ViewControllerPGforiPhoneOS/UsingViewControllersinYourApplication/UsingViewControllersinYourApplication.html

Instantiating a Storyboard's View Controller Programmatically

Listing 2-2 Instantiating another view controller inside the same storyboard

- (IBAction)presentSpecialViewController:(id)sender {
    UIStoryboard *storyboard = self.storyboard;
    SpecialViewController *svc = [storyboard instantiateViewControllerWithIdentifier:@"SpecialViewController"];

    // Configure the new view controller here.

    [self presentViewController:svc animated:YES completion:nil];
}

Answer 4

I suggest that you should create a base view controller which will be subclassed by every controller that needs the login view controller. Then in your base viewController you can create a method like this:

-(YourLoginViewController*)giveMeTheLoginController {
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"YourStoryboardName" bundle:nil];
    YourLoginViewController *viewController = [storyboard instantiateViewControllerWithIdentifier:@"YourLoginViewControllerIdentifier"];
    return viewController;
}

If you don't want another base view controller you can use the same method in your view controllers to obtain a new instance of the view controller from storyboard.

Also using the segues from each view controller is a good way, the segues are used to define your navigation.