UILongPressGestureRecognizer 不做任何事情

Question

我希望 UI 按钮仅在按住超过设定的秒数时才响应。所以我就这样使用了 UILongPressGestureRecognizer：

import UIKit

class ViewController: UIViewController {

@IBOutlet weak var holdButton: UIButton!

@IBAction func holdButtonPressed(_ sender: Any) {
    let recognizer = UILongPressGestureRecognizer(target: self, action: #selector(longPressHappened))
    recognizer.minimumPressDuration = 2.0
    view.addGestureRecognizer(recognizer)
}

和处理程序

@objc func longPressHappened(gestureReconizer: UILongPressGestureRecognizer){
    holdButton.backgroundColor = #colorLiteral(red: 0.7254902124, green: 0.4784313738, blue: 0.09803921729, alpha: 1)
    DispatchQueue.main.async {
         print ("Sucess")
    }
   
}

如您所见，我使用了 DispatchQueue 并尝试更改按钮的颜色，但都不起作用。谁能告诉我为什么？

更新：- 我对实现答案中给出的方法感到困惑，所以我想我会再次给出我的完整代码

import UIKit

class ViewController: UIViewController {

@IBOutlet weak var holdButton: UIButton! {
didSet {
    
         let recognizer = UILongPressGestureRecognizer(target: self,action: #selector(longPressHappened))
         recognizer.minimumPressDuration = 2.0
         holdButton.addGestureRecognizer(recognizer)
     }
 }

override func viewDidLoad() {
    super.viewDidLoad()
    
    holdButton.layer.cornerRadius = 150
    holdButton.layer.borderWidth = 1.0
    holdButton.layer.borderColor = #colorLiteral(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
    holdButton.clipsToBounds = true
}


@objc func longPressHappened(gestureReconizer: UILongPressGestureRecognizer){
    holdButton.backgroundColor = #colorLiteral(red: 0.7254902124, green: 0.4784313738, blue: 0.09803921729, alpha: 1)
    DispatchQueue.main.async {
         print ("Sucess")
    }
   
}

}

Answer 1

你需要给按钮而不是视图添加手势

@IBOutlet weak var holdButton: UIButton! {
      didSet {
            let recognizer = UILongPressGestureRecognizer(target: self,action: #selector(longPressHappened))
            recognizer.minimumPressDuration = 2.0
            holdButton.addGestureRecognizer(recognizer)
        }
    }

Answer 2

改为在您的viewDidLoad 中添加手势：

override func viewDidLoad() {
    super.viewDidLoad()
    //...
    let recognizer = UILongPressGestureRecognizer(target: self,action: #selector(longPressHappened))
    recognizer.minimumPressDuration = 2.0
    holdButton.addGestureRecognizer(recognizer)
}

Answer 3

整个问题是因为您使用UIBUtton 进行手势识别。 UILongPressGestureRecognizer 必须使用 Uiview。

如果你想要UIButton 这样的动画，那么你必须使用手动动画，或者你可以准备好从互联网上制作代码。

如果您需要进一步的帮助，您可以在评论中提问

Answer 4

所以我在查看其他答案，发现所有答案都在 Objective-C 中，这就是我发布这个问题的原因......所以因为答案对我不起作用，我使用 Swiftify 将代码从 @ 987654321@，经过一些修改，成功了。

这里是代码sn-p

    override func viewDidLoad() {
        super.viewDidLoad()
        //...
       let longPress_gr = UILongPressGestureRecognizer(target: self, action: #selector(doAction(_:)))
       longPress_gr.minimumPressDuration = 2 // triggers the action after 2 seconds of press
       holdButton.addGestureRecognizer(longPress_gr)
}

然后是objective-c函数，以确保代码仅在长按发生后触发一次

@objc func doAction(_ recognizer: UILongPressGestureRecognizer?) {

    if recognizer?.state == .began {
        print("sucess")
    }
}

（但是，我无法理解这个答案与上面给出的一些答案之间的区别......有人可以评论它是如何工作的）

Answer 5

您只需要使用 UIView 创建自定义按钮。向该视图添加长按手势，并在所需时间触发委托/闭包。

func addLongPressGesture() {
    let recognizer = UILongPressGestureRecognizer(target: self, action: #selector(handleLongPress(_:)))
    recognizer.minimumPressDuration = 3.0 // Duration
    customButton.addGestureRecognizer(recognizer)
}

@objc
func handleLongPress(_ gestureRecognizer: UILongPressGestureRecognizer) {
    if gestureRecognizer.state == .began {
        // Perform your functionality here
    }
}