Instantiate and Present a viewController in Swift

问题:

Issue

I started taking a look of the new Swift on Xcode 6, and I tried some demo projects and tutorials. Now I am stuck at:

Instantiating and then presenting a viewController from a specific storyboard

Objective-C Solution

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@\"myStoryboardName\" bundle:nil];
UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@\"myVCID\"];
[self presentViewController:vc animated:YES completion:nil];

How to achieve this on Swift?

回答1:

It all is a matter of the new syntax, functionality hasn\'t changed:

// Swift 3.0

let storyboard = UIStoryboard(name: \"MyStoryboardName\", bundle: nil)
let controller = storyboard.instantiateViewController(withIdentifier: \"someViewController\")
self.present(controller, animated: true, completion: nil)

If you\'re having problems with init(coder:), please refer to EridB\'s answer.

回答2:

For people using @akashivskyy\'s answer to instantiate UIViewController and are having the exception:

fatal error: use of unimplemented initializer \'init(coder:)\' for class

Quick tip:

Manually implement required init?(coder aDecoder: NSCoder) at your destination UIViewController that you are trying to instantiate

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

If you need more description please refer to my answer here

回答3:

This link has both the implementations:

Swift:

let viewController:UIViewController = UIStoryboard(name: \"Main\", bundle: nil).instantiateViewControllerWithIdentifier(\"ViewController\") as UIViewController
self.presentViewController(viewController, animated: false, completion: nil)

Objective C

UIViewController *viewController = [[UIStoryboard storyboardWithName:@\"MainStoryboard\" bundle:nil] instantiateViewControllerWithIdentifier:@\"ViewController\"];

This link has code for initiating viewcontroller in the same storyboard

/*
 Helper to Switch the View based on StoryBoard
 @param StoryBoard ID  as String
*/
func switchToViewController(identifier: String) {
    let viewController = self.storyboard?.instantiateViewControllerWithIdentifier(identifier) as! UIViewController
    self.navigationController?.setViewControllers([viewController], animated: false)

}

回答4:

akashivskyy\'s answer works just fine! But, in case you have some trouble returning from the presented view controller, this alternative can be helpful. It worked for me!

Swift:

let storyboard = UIStoryboard(name: \"MyStoryboardName\", bundle: nil)
let vc = storyboard.instantiateViewControllerWithIdentifier(\"someViewController\") as! UIViewController
// Alternative way to present the new view controller
self.navigationController?.showViewController(vc, sender: nil)

Obj-C:

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@\"MyStoryboardName\" bundle:nil];
UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@\"someViewController\"];
[self.navigationController showViewController:vc sender:nil];

回答5:

// \"Main\" is name of .storybord file \"
let mainStoryboard: UIStoryboard = UIStoryboard(name: \"Main\", bundle: nil)
// \"MiniGameView\" is the ID given to the ViewController in the interfacebuilder
// MiniGameViewController is the CLASS name of the ViewController.swift file acosiated to the ViewController
var setViewController = mainStoryboard.instantiateViewControllerWithIdentifier(\"MiniGameView\") as MiniGameViewController
var rootViewController = self.window!.rootViewController
rootViewController?.presentViewController(setViewController, animated: false, completion: nil)

This worked fine for me when i put it in AppDelegate

回答6:

If you want to present it modally, you should have something like bellow:

let vc = self.storyboard!.instantiateViewControllerWithIdentifier(\"YourViewControllerID\")
self.showDetailViewController(vc as! YourViewControllerClassName, sender: self)

回答7:

If you have a Viewcontroller not using any storyboard/Xib, you can push to this particular VC like below call :

 let vcInstance : UIViewController   = yourViewController()
 self.present(vcInstance, animated: true, completion: nil)

回答8:

Swift 4:

    let storyboard = UIStoryboard(name: \"Main\", bundle: nil)
    let yourVC: YourVC = storyboard.instantiateViewController(withIdentifier: \"YourVC\") as! YourVC

回答9:

I would like to suggest a much cleaner way. This will be useful when we have multiple storyboards

1.Create a structure with all your storyboards

struct Storyboard {
      static let main = \"Main\"
      static let login = \"login\"
      static let profile = \"profile\" 
      static let home = \"home\"
    }

2. Create a UIStoryboard extension like this

extension UIStoryboard {
  @nonobjc class var main: UIStoryboard {
    return UIStoryboard(name: Storyboard.main, bundle: nil)
  }
  @nonobjc class var journey: UIStoryboard {
    return UIStoryboard(name: Storyboard.login, bundle: nil)
  }
  @nonobjc class var quiz: UIStoryboard {
    return UIStoryboard(name: Storyboard.profile, bundle: nil)
  }
  @nonobjc class var home: UIStoryboard {
    return UIStoryboard(name: Storyboard.home, bundle: nil)
  }
}

Give the storyboard identifier as the class name, and use the below code to instantiate

let loginVc = UIStoryboard.login.instantiateViewController(withIdentifier: \"\\(LoginViewController.self)\") as! LoginViewController

回答10:

I know it\'s an old thread, but I think the current solution (using hardcoded string identifier for given view controller) is very prone to errors.

I\'ve created a build time script (which you can access here), which will create a compiler safe way for accessing and instantiating view controllers from all storyboard within the given project.

For example, view controller named vc1 in Main.storyboard will be instantiated like so:

let vc: UIViewController = R.storyboard.Main.vc1^  // where the \'^\' character initialize the controller

回答11:

Swift 3

let settingStoryboard : UIStoryboard = UIStoryboard(name: \"SettingViewController\", bundle: nil)
let settingVC = settingStoryboard.instantiateViewController(withIdentifier: \"SettingViewController\") as! SettingViewController
self.present(settingVC, animated: true, completion: {

})

回答12:

No matter what I tried, it just wouldn\'t work for me - no errors, but no new view controller on my screen either. Don\'t know why, but wrapping it in timeout function finally made it work:

DispatchQueue.main.asyncAfter(deadline: .now() + 0.0) {
    let storyboard = UIStoryboard(name: \"Main\", bundle: nil)
    let controller = storyboard.instantiateViewController(withIdentifier: \"TabletViewController\")
    self.present(controller, animated: true, completion: nil)
}

回答13:

I created a library that will handle this much more easier with better syntax:

https://github.com/Jasperav/Storyboardable

Just change Storyboard.swift and let the ViewControllers conform to Storyboardable.

回答14:

Swift 4.2 updated code is

let storyboard = UIStoryboard(name: \"StoryboardNameHere\", bundle: nil)
let controller = storyboard.instantiateViewController(withIdentifier: \"ViewControllerNameHere\")
self.present(controller, animated: true, completion: nil)