// MainVc
let button = UIButton.init(type: UIButtonType.Custom)
button.frame = CGRectMake(20, 100, 50, 50);
button.backgroundColor = UIColor.cyanColor()
self.view.addSubview(button)
button.addTarget(self, action: Selector("click:"), forControlEvents: UIControlEvents.TouchUpInside)

textField = UITextField.init
 
(frame: CGRectMake(20, 160, 100, 50));
self.view.addSubview(textField)
textField.placeholder = "I am Placehoder"

func addressThatTakesAClosure(string:String) ->Void{
        textField.text = string
    }

func click(sender: UIButton)
    {
        // 初始化
        let sec = MainViewController()
        // 類似於屬性傳值
 

        sec.string = "Success"

        /***********************************************/
        //  ---------------華麗的分割線----------------  //
        // 用函式把地址傳過去, 用於回撥
        // sec.initWithClosure(addressThatTakesAClosure)
        // 或者直接這樣
        sec.myClosure = addressThatTakesAClosure
        self.navigationController?.pushViewController(sec, animated: true
 
)
    }

// SecVc
// 類似於OC中的typedef
    typealias sendValueClosure = (string:String)->Void

    var string = ""
    // 宣告一個Closure(閉包)
    var myClosure:sendValueClosure?
    // 下面這個方法需要傳入上個介面的addressThatTakesAClosure函式指標
    func initWithClosure(closure:sendValueClosure?){
        myClosure = closure
    }

    // 類似於OC中的屬性傳值
    print("Success: \(string)")
    let label = UILabel.init(frame: CGRectMake(10, 100, 150, 30))
    label.text = string
    self.view.addSubview(label)

func backButtonCreate()
    {
        // 返回按鈕
     var buttonRight = UIButton()
     buttonRight = UIButton.init(type: UIButtonType.Custom)
     buttonRight.backgroundColor = UIColor.redColor()
     buttonRight.frame = CGRectMake(280, 100, 50, 50)
     self.view.addSubview(buttonRight)
     buttonRight.setTitle("返回", forState: UIControlState.Normal)
     buttonRight.addTarget(self, action: Selector("click"), forControlEvents: UIControlEvents.TouchUpInside)
    }

// 返回點選方法
func click()
    {
        if myClosure != nil{
            myClosure!(string: string);
        }                                                    self.navigationController?.popToRootViewControllerAnimated(true)
    }