选择器“touchesBegan:withEvent:”的覆盖方法具有不兼容的类型“（NSSet，UIEvent）->（）”

Question

Xcode 6.3。在实现 UITextFieldDelegate 协议的类中，我想覆盖 touchesBegan() 方法以可能隐藏键盘。如果我在函数规范中避免了编译器错误，则尝试从 Set 或 NSSet 读取“触摸”时会出现编译器错误，否则 super.touchesBegan(touches , withEvent:event) 会引发错误。在 Xcode 6.2 中编译的这些组合之一！ （那么 Swift "Set" 的文档在哪里以及如何从中获取元素？）

 override func touchesBegan(touches: NSSet, withEvent event: UIEvent) { 
    // Hiding the Keyboard when the User Taps the Background
        if let touch =  touches.anyObject() as? UITouch {
            if nameTF.isFirstResponder() && touch.view != nameTF {
                nameTF.resignFirstResponder();
            }
        }
        super.touchesBegan(touches , withEvent:event)
    }

试试：

override func touchesBegan(touches: NSSet, withEvent event: UIEvent) or
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent) 

编译器错误： 选择器“touchesBegan:withEvent:”的覆盖方法具有不兼容的类型“（NSSet，UIEvent）->（）” 和

super.touchesBegan(touches , withEvent:event)

也抱怨

'NSSet' 不能隐式转换为 'Set'；您的意思是使用 'as' 来显式转换吗？

试试：

override func touchesBegan(touches: Set<AnyObject>, withEvent event: UIEvent) 

编译器错误： 类型 'AnyObject' 不符合协议 'Hashable'

试试：

override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) 

编译器错误

if let touch = touches.anyObject() as? UITouch 

“Set”没有名为“anyObject”的成员，但函数规范和对 super() 的调用都可以！

试试：

override func touchesBegan(touches: NSSet<AnyObject>, withEvent event: UIEvent) -> () or
override func touchesBegan(touches: NSSet<NSObject>, withEvent event: UIEvent) 

编译器错误： 无法专门化非泛型类型“NSSet”

Answer 1

Swift 1.2 (Xcode 6.3) 引入了一个原生的 Set 类型来桥接 与NSSet。这在Swift blog 和 Xcode 6.3 release notes，但显然尚未添加到官方文档中（更新：正如Ahmad Ghadiri noted，它已记录在案）。

UIResponder 方法现在声明为

func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent)

你可以像这样覆盖它：

override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
    if let touch = touches.first as? UITouch {
        // ...
    }
    super.touchesBegan(touches , withEvent:event)
}

Swift 2 (Xcode 7) 更新：（比较 Override func error in Swift 2）

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
    if let touch = touches.first {
        // ...
    }
    super.touchesBegan(touches, withEvent:event)
}

Swift 3 更新：

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        // ...
    }
    super.touchesBegan(touches, with: event)
}

Answer 2

对我有用的是：

    override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
        if let touch = touches.first as? UITouch {
            // ...
        }

        super.touchesBegan(touches , withEvent:event!)
    }

Answer 3

它现在位于 Apple API 参考 here 中，对于 xCode 6.3 版和 swift 1.2 中的覆盖，您可以使用以下代码：

override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
    if let touch =  touches.first as? UITouch {
         // ...
    }
    // ...
}

Answer 4

目前的最新版本是 2015 年 12 月 19 日 xCode 7.2 Swift 2.1 的最新更新。

下次您再次遇到此类错误时，请删除该函数并再次开始输入“touchesBe...”，xCode 应该会自动为您完成它到最新的错误，而不是尝试修复旧的错误。

override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {

    for touch: AnyObject! in touches {
        let touchLocation = touch.locationInNode(self)

        //Use touchLocation for example: button.containsPoint(touchLocation) meaning the user has pressed the button.
    }
}

Answer 5

使用 xCode 7 和 swift 2.0，使用以下代码：

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {

    if let touch =  touches.first{
        print("\(touch)")
    }
    super.touchesBegan(touches, withEvent: event)
}

override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {

    if let touch = touches.first{
        print("\(touch)")
    }
    super.touchesEnded(touches, withEvent: event)
}

override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {

    if let touch = touches.first{
        print("\(touch)")
    }
    super.touchesMoved(touches, withEvent: event)
}

Answer 6

少量添加。为了快速编译无错误，您需要添加

导入 UIKit.UIGestureRecognizerSubclass

Answer 7

使用 Swift 3 和 Xcode 8

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {

}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {

}

override func touchesCancelled(_ touches: Set<UITouch>?, with event: UIEvent?) {
// Don't forget to add "?" after Set<UITouch>
}

Answer 8

使用 Swift 4 和 Xcode 9

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

}

Answer 9

  override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

        if let touch = touches.first as? UITouch {

            if touch.view == self.view{
                self.dismiss(animated: true, completion: nil)
            }
        }
    }