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[英]Value of type 'UIGestureRecognizer' has no member 'numberOfTapsRequired' Why am I getting this error?
[英]Type 'UIGestureRecognizer' has no member 'State'
我在LongPressViewController
类中收到以下错误。
import UIKit
class LongPressViewController: UIViewController {
@IBOutlet weak var imgView: UIImageView!
@IBAction func btnTekan(_ sender: UILongPressGestureRecognizer) {
if sender.state == UIGestureRecognizer.State.began {
let alertController = UIAlertController(title: nil, message: "Long Press terdeteksi", preferredStyle: .alert)
alertController.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
self.present(alertController, animated: true)
}
}
override func viewDidLoad() {
super.viewDidLoad()
let longPressGesture = UILongPressGestureRecognizer(target: self, action: #selector(handleLongPress(_:)))
}
@objc func handleLongPress(_ recognizer: UILongPressGestureRecognizer){
switch recognizer.state {
case .began:
UIView.animate(withDuration: 0.05,
animations: {
self.imgView.transform = CGAffineTransform(scaleX: 1.5, y: 1.5)
},
completion: nil)
case .ended:
UIView.animate(withDuration: 0.05) {
self.imgView.transform = CGAffineTransform.identity
}
default:
break
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
您应该指出在代码的哪一行报告了什么错误。
longPressGesture
,您的代码可能会警告您从未使用在viewDidLoad()
声明和初始化的常量longPressGesture
。 这不是错误,只是友好提醒,此行无效。 您可以通过添加以下行将识别器附加到受控视图:
view.addGestureRecognizer(longPressGesture)
或者,你可以声明longPressGesture
作为@IBOutlet
和界面生成器,将其固定。
进一步使用State
,属性state
已经暗示了UIGestureRecognizer.State
类型,因此您可以将行缩短为
if sender.state == .began {
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