将现有和活动的手势识别器传递给模态视图控制器

Posted 2023-03-13

【中文标题】将现有和活动的手势识别器传递给模态视图控制器

【英文标题】：Passing an existing and active gesture recognizer to a modal view controller

【发布时间】：2015-04-09 17:50:30

【问题描述】：

我想长按启动模态视图，然后在取消长按时关闭模态视图。我该怎么做？

我尝试将 longPressRecognizer 传递给模态视图并 将其设置为委托，但这不起作用。 我尝试了一些更简单的方法 - 检测 touchesEnded，这意味着在模态视图中触摸结束，但这也不会触发。

有没有办法告诉模态视图一个手势已经开始？我希望您识别此手势或触摸的结束/取消？

---

ViewController.swift

import UIKit

class ViewController: UIViewController, UIGestureRecognizerDelegate 
    var buttonView:UIView!
    var longPressRecognizer:UILongPressGestureRecognizer!

    override func viewDidLoad() 
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        self.longPressRecognizer = UILongPressGestureRecognizer(target: self, action: "longPressed:")
        self.longPressRecognizer.delegate = self
        self.view.addGestureRecognizer(self.longPressRecognizer)

        // Add a button
        buttonView = UIView(frame: CGRect(x: 0, y: 0, width: self.view.frame.width, height: 100))
        buttonView.userInteractionEnabled = true;
        buttonView.backgroundColor = UIColor.grayColor()
        self.view.addSubview(buttonView)
    

    func longPressed(recognizer: UILongPressGestureRecognizer) 
        let point: CGPoint = recognizer.locationInView(self.view)
        if let pressedView = self.view.hitTest(point, withEvent: nil) 
            if pressedView == self.buttonView 
                switch recognizer.state 
                case .Began:
                    NSLog("long pressed - Began")
                    var mediaViewController = MediaViewController()
                    self.presentViewController(mediaViewController, animated: false, completion: nil)
                case .Cancelled:
                    NSLog("long pressed - Cancelled")
                case .Ended:
                    NSLog("long pressed - Ended")
                default:
                    break
                
            
        
    

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

MediaViewController.swift

import UIKit

class MediaViewController: UIViewController, UIGestureRecognizerDelegate 
    var longPressRecognizer:UILongPressGestureRecognizer!

    override func viewDidLoad() 
        super.viewDidLoad()
        self.view.backgroundColor = UIColor.lightGrayColor()

        self.longPressRecognizer = UILongPressGestureRecognizer(target: self, action: "longPressed:")
        self.longPressRecognizer.delegate = self
        self.view.addGestureRecognizer(self.longPressRecognizer)
    

    func longPressed(recognizer: UILongPressGestureRecognizer) 
        switch recognizer.state 
        case .Began:
            NSLog("long pressed - Began")
        case .Cancelled:
            NSLog("long pressed - Cancelled")
        case .Ended:
            NSLog("long pressed - Ended")
            self.dismissViewControllerAnimated(false, completion: nil)
        default:
            break
        
    

    override func touchesBegan(touches: NSSet, withEvent event: UIEvent) 
        NSLog("touches began")
    

    override func touchesEnded(touches: NSSet, withEvent event: UIEvent) 
        NSLog("touches ended")
    

【问题讨论】：

一个笨拙的解决方法可能是引用模态视图控制器并创建一个viewController 可以调用并传递触摸事件信息的方法。您需要在您的viewController 实现中处理.Changed 识别器状态，您将在模式视图控制器上调用您的方法。

是的，这是一个非常基本的版本。有人告诉我这很脆弱，但没有证据支持。

【参考方案1】：

嗯，这似乎可以在长按的同时处理轻按手势。还不错！

---

ViewController.swift

import UIKit

class ViewController: UIViewController, UIGestureRecognizerDelegate 
    var buttonView:UIView!
    var longPressRecognizer:UILongPressGestureRecognizer?

    override func viewDidLoad() 
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        // Add a button
        buttonView = UIView(frame: CGRect(x: 0, y: 0, width: self.view.frame.width, height: 100))
        buttonView.userInteractionEnabled = true;
        buttonView.backgroundColor = UIColor.grayColor()
        self.view.addSubview(buttonView)
    

    override func viewDidAppear(animated: Bool) 
        if let recognizer  = self.longPressRecognizer 
            // Reuse existing recognizer
            self.longPressRecognizer = recognizer
            recognizer.removeTarget(nil, action: nil)
            recognizer.addTarget(self, action: "longPressed:")
            recognizer.delegate = self
            self.view.addGestureRecognizer(recognizer)
         else 
            // Create a new new recognizer
            self.longPressRecognizer = UILongPressGestureRecognizer(target: self, action: "longPressed:")
            self.longPressRecognizer!.delegate = self
            self.view.addGestureRecognizer(self.longPressRecognizer!)
        
    

    override func viewDidDisappear(animated: Bool) 
        // Remove the recognizer
        if let recognizer = self.longPressRecognizer 
            self.view.removeGestureRecognizer(recognizer)
        
    

    func longPressed(recognizer: UILongPressGestureRecognizer) 
        let point: CGPoint = recognizer.locationInView(self.view)
        if let pressedView = self.view.hitTest(point, withEvent: nil) 
            if pressedView == self.buttonView 
                switch recognizer.state 
                case .Began:
                    NSLog("ViewController: long pressed - Began")
                    var mediaViewController = MediaViewController()
                    mediaViewController.addRecognizer(recognizer)
                    self.presentViewController(mediaViewController, animated: false, completion: nil)
                case .Cancelled:
                    NSLog("ViewController: long pressed - Cancelled")
                case .Ended:
                    NSLog("ViewController: long pressed - Ended")
                case .Changed:
                    NSLog("ViewController: long pressed - Changed")
                default:
                    break
                
            
        
    

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

MediaViewController.swift

class MediaViewController: UIViewController, UIGestureRecognizerDelegate 
    var longPressRecognizer: UILongPressGestureRecognizer!
    var tapRecognizer: UITapGestureRecognizer!

    override func viewDidLoad() 
        super.viewDidLoad()
        self.view.backgroundColor = UIColor.lightGrayColor()

        self.tapRecognizer = UITapGestureRecognizer(target: self, action: "tap:")
        self.tapRecognizer.cancelsTouchesInView = false
        self.tapRecognizer.delegate = self
        self.view.addGestureRecognizer(self.tapRecognizer)

        self.longPressRecognizer.removeTarget(nil, action: nil)
        self.longPressRecognizer.addTarget(self, action: "longPressed:")
        self.longPressRecognizer.delegate = self
        self.view.addGestureRecognizer(self.longPressRecognizer)
    

    override func viewWillDisappear(animated: Bool) 
        // Remove gesture recognizers
        self.view.removeGestureRecognizer(self.longPressRecognizer)
        self.longPressRecognizer.delegate = nil
        self.view.removeGestureRecognizer(self.tapRecognizer)
        self.tapRecognizer.delegate = nil
    

    func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWithGestureRecognizer otherGestureRecognizer: UIGestureRecognizer) -> Bool 
        return true;
    

    func longPressed(recognizer: UILongPressGestureRecognizer) 
        switch recognizer.state 
        case .Began:
            NSLog("MediaViewController: long pressed - Began")
        case .Cancelled:
            NSLog("MediaViewController: long pressed - Cancelled")
        case .Ended:
            NSLog("MediaViewController: long pressed - Ended")
            self.dismissViewControllerAnimated(false, completion: nil)
        case .Changed:
            NSLog("MediaViewController: long pressed - Changed")
        default:
            break
        
    

    func tap(recongizer: UITapGestureRecognizer) 
        if (self.view.backgroundColor == UIColor.lightGrayColor()) 
            self.view.backgroundColor = UIColor.greenColor()
         else 
            self.view.backgroundColor = UIColor.lightGrayColor()
        
    

    func addRecognizer(recognizer: UILongPressGestureRecognizer) 
        self.longPressRecognizer = recognizer
    

【讨论】：

谢谢！你拯救了我的一天！