Question

enter image description here 我使用的是Swift 1.2

我尝试使用此fiddle以及接受答案的第2条评论中的链接。

我使用带有自动布局的故事板，我在自定义类中为UIScrollView设置了自定义类。

我在UIViewController中没有收到任何包含我的自定义UIScrollView的触摸事件

编辑：更新了我的代码，了解我如何使用@Victor Sigler的答案。

自定义ScrollView代码：

import UIKit

protocol PassTouchesScrollViewDelegate {

func scrollTouchBegan(touches: Set<NSObject>, withEvent event: UIEvent)
func scrollTouchMoved(touches: Set<NSObject>, withEvent event: UIEvent)
}

class PassTouchesScrollView: UIScrollView {

var delegatePass : PassTouchesScrollViewDelegate?

override init(frame: CGRect) {
    super.init(frame: frame)
}

required init(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
}

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

    self.delegatePass?.scrollTouchBegan(touches, withEvent: event)


}

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

    self.delegatePass?.scrollTouchMoved(touches, withEvent: event)

}

}

我的ViewController：

import UIKit

class ViewController: UIViewController, PassTouchesScrollViewDelegate {

@IBOutlet weak var scrollView: UIScrollView!

override func viewDidLoad() {
    super.viewDidLoad()

    scrollView.delegatePass = self
}

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

    println("began \(touches)")

}

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

    println("moved \(touches)")
}     

}

我试图让用户在UIImage上绘制一条线，我使用PanGesture识别器工作，但性能非常差，特别是在较旧的硬件上，我按照Ray Wenderlich教程使用触摸开始并且性能要好得多，但它是在UIView而不是ScrollView上。我需要一个UIScrollView，因为在用户绘制图像之前，他们可以放大和围绕它。

Answer 1

我以为你在考虑这个错误。如果您想知道UIScrollView何时移动，则无需将其子类化。 iOS已在UIScrollViewDelegate。

内设置了您需要的所有方法

您必须实施UISCrollViewDelegate以获取有关UIScrollView中的操作的通知，并通过Interface Builder或代码设置delegate，由您自己决定。

请参阅以下示例以了解如何执行此操作：

class ViewController: UIViewController, UIScrollViewDelegate {

     @IBOutlet weak var scrollView: UIScrollView!

     override func viewDidLoad() {
       super.viewDidLoad()
       self.scrollView.delegate = self
     }
}

如果你想知道你上面解释的方式，你必须遵循以下步骤：

您必须像在类UIScrollView中那样从PassTouchesScrollView类创建子类并实现委托模式，以便通过以下方式通知UIScrollView：

import UIKit

protocol PassTouchesScrollViewDelegate {
   func touchBegan()
   func touchMoved()
}


class PassTouchesScrollView: UIScrollView {

  var delegatePass : PassTouchesScrollViewDelegate?

  override init(frame: CGRect) {
    super.init(frame: frame)
  }

  required init(coder aDecoder: NSCoder) {
     super.init(coder: aDecoder)
  }

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

     // Notify it's delegate about touched
     self.delegatePass?.touchBegan()

    if self.dragging == true {
       self.nextResponder()?.touchesBegan(touches, withEvent: event)
    } else {
       super.touchesBegan(touches, withEvent: event)
    }

 }

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

     // Notify it's delegate about touched
     self.delegatePass?.touchMoved()

     if self.dragging == true {            
        self.nextResponder()?.touchesMoved(touches, withEvent: event)
     } else {            
       super.touchesMoved(touches, withEvent: event)
     }
  }   
}

您的课程ViewController必须按以下方式实施：

class ViewController: UIViewController, UIScrollViewDelegate {

  @IBOutlet weak var scrollView: PassTouchesScrollView!

  override func viewDidLoad() {
    super.viewDidLoad()        
    scrollView.delegate = self  
    scrollView.delegatePass = self      
  }

  override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
  }

  func touchMoved() {
     println("touch moved")
  }

  func touchBegan() {
     println("touch began")
  }

}

您必须在界面生成器中选择您的UIScrollView，并在类部件的Identity Inspector中将其设置为类PassTouchesScrollView。

您应该在控制台中看到以下内容：

touch began
touch began
touch began
touch began
touch began
touch began
touch moved
touch move

我希望这对你有所帮助。

Answer 2

试试这个

  extension UIScrollView {

    override open func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        self.next?.touchesBegan(touches, with: event)
        print("touchesBegan")
    }

    override open func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        self.next?.touchesMoved(touches, with: event)
        print("touchesMoved")
    }

    override open func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        self.next?.touchesEnded(touches, with: event)
        print("touchesEnded")
    }

}

Answer 3

touchesBegan仅适用于UIView的子类。从UIViewController中取出它以使其工作。

UIResponder Apple Docs

Swift中的子类UIScrollView用于触摸开始和放大移动

3 个答案: