代表返回零

Question

我想在swift中使用協議/委託，雖然我沒有收到任何錯誤，但似乎我的委託沒有被創建。

這裏是我的代碼

1級

import UIKit 

protocol GameViewSliding{ 
    func slideGameView() 
} 

class GameDetailsViewController: UIViewController { 

    var delegate:GameViewSliding? 

    override func viewDidLoad() { 
     super.viewDidLoad() 
     // Do any additional setup after loading the view. 
    } 

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

    @IBAction func showOptions(sender: AnyObject) { 

     println("button pressed") 
     println(delegate) 
     delegate?.slideGameView() 
    } 

} 

Class 2標準，符合協議

import UIKit 

var currentHoleNumber:Int = 0 
var parThree = false; 
var parFive = false; 

class GameViewController: UIViewController, GameViewSliding{ 


var gameDetailsVC:GameDetailsViewController = GameDetailsViewController() 
    override func viewDidLoad() { 
     super.viewDidLoad() 

     println("inside the game class") 
     gameDetailsVC.delegate = self 
    } 

    func slideGameView(){ 
     println("this is from the root controller") 
    } 

} 

委託回來了零，這就是爲什麼我從來沒有得到來自的println Class2，不知道爲什麼它是零。

Answer 1

您的GameViewController到類GameDetailsViewController來設置基準，當它應該被提出並設置它的delegate以下列方式：

gameDetailsViewController.delegate = self 

並與該委託它不是nil，當然是請在prepareForSegue中設置參考，或者使用其他方法呈現其他ViewController。

Answer 2

我注意到在使用SplitViewController時設置代理時存在一些問題。從splitViewController的detailVC能夠取得像這樣：

override func viewDidLoad() { 
    super.viewDidLoad() 
    let detailNavigationController = splitViewController?.viewControllers[1] as! UINavigationController 
    let detailVC = detailNavigationController.topViewController as! DetailViewController 

    detailVC.delegate = self 
} 

另一種方法是設置委託在AppDelegate中，在SplitViewController後，後面的行配置：

let masterNavigationController = splitViewController.viewControllers[0] as! UINavigationController 
let masterVC = masterNavigationController.topViewController as! MasterViewController 
let detailNavigationController = splitViewController.viewControllers[1] as! UINavigationController 
let detailVC = detailNavigationController.topViewController as! DetailViewController 

detailVC.delegate = masterVC