单击 alertView 中的按钮时如何导航 ViewController

Question

鉴于下面的代码，当我单击“接受”按钮时，它不会导航到SecondViewController，它只显示黑屏。任何帮助表示赞赏。

   let alertController = UIAlertController(title: tit!, message: "Book Now!", preferredStyle: .Alert)
   let declineAction = UIAlertAction(title: "Decline", style: .Cancel, handler: nil)
   alertController.addAction(declineAction)

   let acceptAction = UIAlertAction(title: "Accept", style: .Default) { (_) -> Void in
        let nv=SecondViewController()
        self.presentViewController(nv, animated:true, completion:nil)
    }
   presentViewController(alertController, animated: true, completion: nil)
   alertController.addAction(acceptAction)

Answer 1

要打开任何UIViewController 必须instantiate 它。而你所做的只是创建类的对象。

这样做：

let nv = self.storyboard!.instantiateViewControllerWithIdentifier("storyboardidentifier") as! SecondViewController
self.presentViewController(nv, animated:true, completion:nil)

这是打开你的UIViewController 随意！

Answer 2

创建一个从当前视图控制器到 SecondViewController 的 segue 链接，并在情节提要中给它一个标识符，您可以使用以下代码

    let alert = UIAlertController(title: "Options", message: "Book Now!", preferredStyle: .Alert)

    alert.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel, handler: nil))
    alert.addAction(UIAlertAction(title: "Accept", style: UIAlertActionStyle.Default, handler: { (alertAction) -> Void in
        self.performSegueWithIdentifier("FirstToSecond", sender: self)

    }))
    self.presentViewController(alert, animated: true, completion: nil)

注意：您的第一个视图控制器将是锚点。

如果您已将 SecondViewController 嵌入到导航控制器中并且还想传递值，则可以添加以下内容

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if segue.identifier == "FirstToSecond" {
        let nav = segue.destinationViewController as! UINavigationController
        let svc = nav.viewControllers[0] as! SecondViewController
        //svc.delegate = self //uncomment this if you need to set a delegate as well
        svc.value = ""
    }
}

这是使用 xCode 7 和 Swift 2。希望这会有所帮助 :)