我想指出两点，这两点一直给我带来麻烦。

I was creating the Gesture Recognizer on init and storing it in a let property. Apparently, adding this gesture recog to the view does not work. May be self object passed to the gesture recognizer during init, is not properly configured. The gesture recognizer should not be added to views with zero frames. I create all my views with zero frame and then resize them using autolayout. The gesture recognizers have to be added AFTER the views have been resized by the autolayout engine. So I add the gesture recognizer in viewDidAppear and they work.

    let tap = UITapGestureRecognizer(target: self, action: Selector("handleFrontTap:"))
    frontView.addGestureRecognizer(tap)

// Make sure this is not private
func handleFrontTap(gestureRecognizer: UITapGestureRecognizer) {
    print("tap working")
}

斯威夫特4

let tap = UITapGestureRecognizer(target: self, action: #selector(self.touchTapped(_:)))
    self.view.addGestureRecognizer(tap)

@objc func touchTapped(_ sender: UITapGestureRecognizer) {
}

你需要用目标和动作初始化UITapGestureRecognizer，如下所示:

let tap = UITapGestureRecognizer(target: self, action: "handleTap:")
tap.delegate = self
myView.addGestureRecognizer(tap)

然后，你应该实现处理程序，它将在每次tap事件发生时被调用:

func handleTap(sender: UITapGestureRecognizer) {
  // handling code
}

实现轻触手势

let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "touchHappen") 
view.userInteractionEnabled = true
view.addGestureRecognizer(tap)

当点击被识别时调用此函数。

func touchHappen() {
    //Causes the view (or one of its embedded text fields) to resign the first responder status.
    self.view.endEditing(true)
}

针对Swift 3 +的更新

let tap = UITapGestureRecognizer(target: self, action: #selector(self.touchHappen(_:)))
yourView.addGestureRecognizer(tap)
yourView.userInteractionEnabled = true

func touchHappen(_ sender: UITapGestureRecognizer) {
    print("Hello Dear you are here")
}

对于Swift 4:

let tap = UITapGestureRecognizer(target: self, action: #selector(self.handleTap(_:)))

view.addGestureRecognizer(tap)

view.isUserInteractionEnabled = true

self.view.addSubview(view)

// function which is triggered when handleTap is called
@objc func handleTap(_ sender: UITapGestureRecognizer) {
    print("Hello World")
}

在Swift 4中，你需要显式地指出触发的函数是可从Objective-C调用的，所以你需要添加@objc你的handleTap函数。

请看@Ali Beadle的回答:Swift 4添加手势:覆盖vs @objc