对UIWebView的双击识别 - Swift 3

Question

我试图在UIWebView上实现手势识别器来检测双击。但没有认可。

我已经浏览了几个教程的Web，我可以编译到这。下面的代码。但没有成功。

class PageContentViewController: UIViewController, UIGestureRecognizerDelegate, UIWebViewDelegate { 

@IBOutlet weak var webView: UIWebView! 

var pageIndex: Int = 0 
var strTitle: String! 
var flag : Int = 0 

override func viewDidLoad() { 
    super.viewDidLoad() 
    webView.delegate = self 

    DispatchQueue.main.async { 
    let req = URLRequest(url: URL(fileURLWithPath: Bundle.main.path(forResource: self.strTitle+"/index" , ofType: "html")!)) 
    self.webView.loadRequest(req) 
    self.view.addSubview(self.webView) 

    } 

    let tapGestureRecognizer = UITapGestureRecognizer(target:self, action:#selector(self.goToback)) 
    tapGestureRecognizer.delegate? = self 
    tapGestureRecognizer.numberOfTapsRequired = 2 
    webView.isUserInteractionEnabled = true 
    webView.addGestureRecognizer(tapGestureRecognizer) 
    webView.scrollView.addGestureRecognizer(tapGestureRecognizer) 
    webView.gestureRecognizerShouldBegin(tapGestureRecognizer) 
} 


func gestureRecognizer(_: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith:UIGestureRecognizer) -> Bool { 
    return true 
} 
func gestureRecognizer(_: UIGestureRecognizer, shouldReceive:UITouch) -> Bool { 
    return true 
} 


func goToback(){ 
    print("On the Back") 
} 

} 

什么是错误的代码？

我很喜欢快速。

在此先感谢

Answer 1

我想你会需要添加

webView.delegate = self 

同时添加UIWebViewDelegate到类

编辑：

你shouldRecognizeSimultaneouslyWith和shouldReceive看起来有点怪异，也许复制粘贴错误？它应该看起来像：

func gestureRecognizer(_: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith:UIGestureRecognizer) -> Bool { 
    return true 
} 
func gestureRecognizer(_: UIGestureRecognizer, shouldReceive:UITouch) -> Bool { 
    return true 
} 

编辑2：

我复制你的确切代码并删除gestureRecognizerShould开始和它的工作，我能除去一些其他的代码为好，如果你需要它在不知道你的项目，但这里是我什么工作：

class ViewController: UIViewController, UIGestureRecognizerDelegate, UIWebViewDelegate { 

@IBOutlet weak var webView: UIWebView! 

override func viewDidLoad() { 
    super.viewDidLoad() 
    webView.delegate = self 

    DispatchQueue.main.async { 
     let req = URLRequest(url: URL(fileURLWithPath: Bundle.main.path(forResource: self.strTitle+"/index" , ofType: "html")!)) 
     self.webView.loadRequest(req) 
    } 

    let tapGestureRecognizer = UITapGestureRecognizer(target:self, action:#selector(self.goToback)) 
    tapGestureRecognizer.delegate = self 
    tapGestureRecognizer.numberOfTapsRequired = 2 
    webView.isUserInteractionEnabled = true 
    webView.addGestureRecognizer(tapGestureRecognizer) 
} 


func gestureRecognizer(_: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith:UIGestureRecognizer) -> Bool { 
    return true 
} 


func goToback() { 
    print("On the Back") 
} 

Answer 2

我有一个双敲击手势在我的应用程序做的工作如下：

我创建UIWe的子类bView那就是UIGestureRecognizerDelegate

class MyWebView: UIWebView, UIGestureRecognizerDelegate { 
    func gestureRecognizer(_: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith:UIGestureRecognizer) -> Bool { 
     return true 
    } 

    func gestureRecognizer(_: UIGestureRecognizer, shouldReceive:UITouch) -> Bool { 
     return true 
    } 
} 

然后在我的视图控制器类我引用我的子类（确保它在Interface Builder中引用）

@IBOutlet weak var webView: MyWebView! 

而且在viewDidLoad中添加识别

let tapGestureRecognizer = UITapGestureRecognizer(target:self, action:#selector(self.goToback)) 
tapGestureRecognizer.delegate? = self.webView //set the delegate to the custom UIWebView 
tapGestureRecognizer.numberOfTapsRequired = 2 
webView.isUserInteractionEnabled = true 
webView.addGestureRecognizer(tapGestureRecognizer) 

希望这有帮助，我的原始代码是在Objective-C代码中，所以不得不在这里做一个快速翻译，所以希望没有语法问题。

Answer 3

为什么你对webview和webview.scrollview使用相同的手势UIGestureRecognizer。

相反，你需要创建两个这样的两个独立UIGestureRecognizer ...

// for webView 
let tapGestureRecognizer = UITapGestureRecognizer(target:self, action:#selector(self.goToback)) 
tapGestureRecognizer.delegate? = self 
tapGestureRecognizer.numberOfTapsRequired = 2 
webView.isUserInteractionEnabled = true 
webView.addGestureRecognizer(tapGestureRecognizer) 

// for webView.scrollView 
let tapGestureRecognizer1 = UITapGestureRecognizer(target:self, action:#selector(self.goToback)) 
tapGestureRecognizer1.delegate? = self 
tapGestureRecognizer1.numberOfTapsRequired = 2 
webView.scrollView.addGestureRecognizer(tapGestureRecognizer1) 

如果您分配相同的手势识别两个对象，然后将对象的一个​​没有它...看到日志

Answer 4

我已经使用这个代码，它完美地

override func viewDidLoad() { 
    super.viewDidLoad() 

    let tapLockGesture = UITapGestureRecognizer(target: self, action: #selector(tapLock))  
    tapLockGesture.delegate = self 
    tapLockGesture.numberOfTapsRequired = 2 
    webView.addGestureRecognizer(tapLockGesture) 

} 

func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool { 
    return true 
} 

对我的作品请务必遵守UIGestureRecognizerDelegate和UIScrollViewDelegate。