使用instantiateViewControllerWithIdentifier和performSegueWithIdentifier之间有什么区别？

Question

这两种方法都可以让我呈现一个新的视图控制器（一种是通过调用presentviewcontroller），因此我不明白它们之间的区别以及何时应该使用它们。

- Michael

---

instantiateViewControllerWithIdentifier做其名称所示的事情; 它实例化一个视图控制器，仅此而已。它不会呈现一个视图控制器。 - rdelmar

@rdelmar 我已经回复了你的评论，为你澄清了。 - Michael

Answer 1

它们都引用了与故事板相关的标识符。主要区别在于，一个(performSegueWithIdentifer)根据segue的终点(即segue指向的位置)实例化一个对象，而另一个(instantiateViewControllerWithIdentifier)根据VC的标识符(而不是segue)实例化一个唯一的VC。

您可以在故事板中的不同位置具有相同标识符的多个segue，而故事板中的VC不能具有相同的标识符。

- Firo

---

由于它们基本上做相同的事情，那么在什么情况下会更倾向于使用其中一个而不是另一个呢？此外，在采用程序化布局的项目中，哪种方法被广泛使用？我猜当您想要特定的UX过渡类型时，您将使用 performSegueWithIdentifer，因为 instantiateViewControllerWithIdentifier 只是一个普通的转换，对吧？ - Edison

通常我认为大多数人会使用performSegueWithIdentifer，因为segue定义了流程。instantiate...使得故事板布局更加不确定（因为你正在用代码定义转换）。如果布局是以编程方式完成的，则通常都不会使用任何一个。只需创建一个类实例并呈现它：例如 let vc = FooVC() ... self.present(vc) - Firo

Answer 2

performSegueWithIdentifier和instantiateViewControllerWithIdentifier都用于从一个viewController移动到另一个viewController。但是它们之间有很大的区别....

1. The identifier of the 1st case defines a segue like push, modal, custom etc which are used to perform a specific type of transition from one VC to another VC. eg.

   self.performSegueWithIdentifier("push", sender: self);`
   

   where "push" is an identifier of a push segue.

   The identifier of the 2nd case defines a VC like myViewController, myTableViewController, myNavigationController etc. 2nd function is used to go to the specific VC ( with identifier.) from a VC in the storyBoard. eg.

   var vc = mainStoryboard.instantiateViewControllerWithIdentifier("GameView") as GameViewController; 
   self.presentViewController(VC, animated: true, completion: nil) ;
   

   where "GameView" is the identifier of GameViewController. Here a instance of GameViewController is created and then the function presentViewController is called to go to the instantiated vc.

2. For the 1st case with the help of segue identifier u can pass one are more values of variables to the next VC. eg.

   override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) 
   {
       if (segue.identifier == "push") 
       {
           let game = segue.destinationViewController as GameViewController
           game.value = self.myvalue // *value* is an Int variable of GameViewController class and *myvalue* is an Int variable of recent VC class.
       }
   }
   

   This funcion is also called when self.performSegueWithIdentifier("push", sender: self); is called to pass the value to GameViewController.

   But in 2nd case it possible directly like,

   var vc = mainStoryboard.instantiateViewControllerWithIdentifier("GameView") as GameViewController; 
   vc.value = self.myvalue;
   self.presentViewController(VC, animated: true, completion: nil) ;
   

- Pritam