將函數傳遞給變量以便稍後可以調用

Question

我目前正在爲我正在處理的應用程序製作自定義的UIView類，並且它要求您傳遞一個將在UIView的。我需要做的就是將函數傳遞給init()函數，並將其存儲起來，以便稍後調用它。我目前正在使用的代碼如下所示：

class CustomUIView: UIView { 

    private var _tapListener : Void; 

    init (tapListener:() -> Void){ 
     //Attempt to set _tapListener variable as tap listener does not work :(
     _tapListener = tapListener(); 
     //Right now it just executes the function :(
     let listener = UITapGestureRecognizer(target: self, action: #selector(callFunction)); 
     self.addGestureRecognizer(listener) 
    } 

    required init?(coder aDecoder: NSCoder) { 
     fatalError("init(coder:) has not been implemented") 
    } 

    func callFunction() { 
     //Call the function here 
     _tapListener(); 
    } 
} 

如何完成我在此嘗試完成的操作？

任何及所有的幫助感激

Answer 1

考慮使用瓶蓋：

typealias tapListenerClosure =() -> Void 

class CustomUIView: UIView { 

    var tapClosure: tapListenerClosure 

    init (tap: @escaping tapListenerClosure) { 
     self.tapClosure = tap 
     super.init(.... 
     let listener = UITapGestureRecognizer(target: self, action: #selector(callFunction)); 
     self.addGestureRecognizer(listener) 
    } 

    required init?(coder aDecoder: NSCoder) { 
     fatalError("init(coder:) has not been implemented") 
    } 

    func callFunction() { 
     //Call the function here 
     self.tapClosure() 
    } 
} 

Answer 2

就以同樣的方式作爲參數的實例變量定義到init：

private var _tapListener:() -> Void