過載gestureRecognizerShouldBegin與UIPanGestureRecognizer在迅速

Question

我有一個平底鍋的手勢，我需要檢查手勢何時開始。在Objective-C，你可以使用

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer 

，並有可能與UIPanGestureRecognizer

- (BOOL)gestureRecognizerShouldBegin:(UIPanGestureRecognizer *)gestureRecognizer 

但在迅疾

override func gestureRecognizerShouldBegin(gestureRecognizer: UIPanGestureRecognizer) -> Bool { 

重載它不工作，並返回

重寫方法與選擇器'gestureRecognizerShouldBegin：'具有不兼容的類型'（UIPanGestureReco gnizer） - > Bool'

如何在swift中重載此方法？

Answer 1

刪除覆蓋，不要忘記添加UIGestureRecognizerDelegate擴展。

您可以在類的底部添加它

class YourViewController: UIViewController { 
    // You class declaration 
} 

extension YourViewController: UIGestureRecognizerDelegate { 
    func gestureRecognizerShouldBegin(gestureRecognizer: UIGestureRecognizer) -> Bool { 
     // 
     return true 
    } 
} 

Answer 2

你並不需要重載的方法，你可以這樣做，而不是：

override func gestureRecognizerShouldBegin(gestureRecognizer: UIGestureRecognizer) -> Bool { 
    if let panGesture = gestureRecognizer as? UIPanGestureRecognizer { 
     return ... 
    } 
    else { 
     return ... 
    } 
}