我有一个UIView并且我添加了点击手势
let tap = UITapGestureRecognizer(target: self, action: Selector("handleTap:"))
tap.delegate = self
myView.addGesture(tap)
我试图在testfile中以编程方式调用它。
sendActionForEvent
我正在使用这个函数，但它不起作用:
myView.sendActionForEvent(UIEvents.touchUpDown)
它显示未识别的选择器发送到实例。
我该如何解决这个问题呢?
当前回答
这是它在Swift 3中的工作原理:
@IBOutlet var myView: UIView!
override func viewDidLoad() {
super.viewDidLoad()
let tap = UITapGestureRecognizer(target: self, action:#selector(handleTap))
myView.addGestureRecognizer(tap)
}
func handleTap() {
print("tapped")
}
其他回答
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
这是它在Swift 3中的工作原理:
@IBOutlet var myView: UIView!
override func viewDidLoad() {
super.viewDidLoad()
let tap = UITapGestureRecognizer(target: self, action:#selector(handleTap))
myView.addGestureRecognizer(tap)
}
func handleTap() {
print("tapped")
}
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")
}
我使用的是Xcode 7.3.1, Swift 2.2。见下文。
func addTapGesture() {
let tap = UITapGestureRecognizer(target: self, action: #selector(MyViewController.handleTap))
tap.numberOfTapsRequired = 1
self.myView.addGestureRecognizer(tap)
}
func handleTap() {
// Your code here...
}
