使用segue在Swift中在ViewControllers之間傳遞數據

Question

我在我正在觀看的教程中完美工作的代碼存在問題。我看到，在本教程中，他們使用的是斯威夫特1我覺得我有斯威夫特2 第一viewcontroler：

import UIKit 

    class ViewController: UIViewController { 

    @IBOutlet weak var textfield1: UITextField! 


    override func viewDidLoad() { 
    super.viewDidLoad() 
    // Do any additional setup after loading the view, typically from a nib. 
    } 

    override func didReceiveMemoryWarning() { 
    super.didReceiveMemoryWarning() 
    // Dispose of any resources that can be recreated. 
    } 

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) { 
    var DestViewController : ViewTwo = segue.destinationViewController as ViewTwo // here is where I get the error 

    } 

我應該怎麼改？ 感謝

Answer 1

var DestViewController : ViewTwo = segue.destinationViewController as ViewTwo // here is where I get the error 

將需要

var destViewController : ViewTwo = segue.destinationViewController as! ViewTwo // here is where I get the error 

通知!as但是這可能會爲Force unwrapping目的地視圖崩潰的ViewTwo在未來的時候也未必。

更換

if let destViewController = segue.destinationViewController as? ViewTwo { 
    //Do stuff to the destination controller here 
}