Question

Xcode 6.3。在实现UITextFieldDelegate协议的类中，我想重写touchesBegan（）方法以隐藏键盘。如果我在函数规范中避免了编译器错误，那么在尝试读取＆＃34; touch＆＃34;时会出现编译错误。从Set或NSSet，或super.touchesBegan（touches，withEvent：event）抛出错误。在Xcode 6.2中编译的这些组合之一！（那么Swift的文档在哪里？＃34; Set＆＃34;以及如何从一个元素中获取元素？）

 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)
    }

尝试：

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

编译器错误：使用selector＆＃39; touchesBegan：withEvent：＆＃39;覆盖方法具有不兼容的类型＆＃39;（NSSet，UIEvent） - ＆gt; （）＆＃39; 和

super.touchesBegan(touches , withEvent:event)

也抱怨

＆＃39;的NSSet＆＃39;不能隐含地转换为＆＃39; Set＆＃39 ;;你的意思是使用＆＃39;作为＆＃39;明确转换？

尝试：

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

编译器错误：输入＆＃39; AnyObject＆＃39;不符合协议＆＃39; Hashable＆＃39;

尝试：

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

编译错误

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

＆＃39;设置＆＃39;没有名为＆＃39; anyObject＆＃39;的成员但是功能规范和对super（）的调用都没问题！

尝试：

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

编译器错误：不能专门化非泛型类型＆＃39; NSSet＆＃39;

Answer 1

Swift 1.2（Xcode 6.3）引入了桥接的本地Set类型与NSSet。这在Swift blog和Xcode 6.3 release notes中提到 Ahmad Ghadiri noted，~~但显然尚未添加到官方文档~~（更新：作为Override func error in Swift 2，现在已记录）。

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)
}

更新Swift 2（Xcode 7）：（比较{{3}}）

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

Swift 3的更新：

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

Answer 2

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 3

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 4

它现在位于Apple API参考here中，并且在xCode版本6.3和swift 1.2中覆盖，您可以使用此代码：

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

Answer 5

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 6

小补充。对于swift编译没有错误，你需要添加

导入UIKit.UIGestureRecognizerSubclass

Answer 7

使用 Swift 4 和 Xcode 9

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

}

Answer 8

  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)
            }
        }
    }

使用selector＆＃39; touchesBegan：withEvent：＆＃39;覆盖方法具有不兼容的类型＆＃39;（NSSet，UIEvent） - ＆gt; （）＆＃39;

8 个答案: