Swift：Dictionary Key as CGRect

Question

我需要將button的frame保存爲密鑰，將index保存爲value。下面是代碼：

var buttonLocationWithIndex = Dictionary<CGRect, Int>() 

override func viewDidAppear(animated: Bool) { 
    super.viewDidAppear(animated) 

    for (index, point) in enumerate(self.points){ 
     let pointButton = UIButton() 
     pointButton.frame = point.bounds 
     self.buttonLocationWithIndex[point.frame] = index 
     self.view.addSubview(pointButton) 
    } 

我越來越想申報字典時出現錯誤：Type 'CGRect' does not confirm to protocol 'Hashable'

UPDATE

func pressed(sender: UIButton!) { 
    var alertView = UIAlertView(); 

    alertView.addButtonWithTitle("Ok"); 
    alertView.title = "title"; 
    var boundsIndex = self.buttonLocationWithIndex[sender.frame] 
    var value = self.points(boundsIndex) 
    alertView.message = value 
    alertView.show(); 
} 

錯誤：Cannot invoke points with an arguments list of type (Int?)'

Answer 1

實施Hashable協議CGRect通過擴展。

extension CGRect: Hashable { 
    public var hashValue: Int { 
     return NSStringFromCGRect(self).hashValue 
    } 
} 

它將允許您使用CGRect作爲關鍵。