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How to call gesture tap on UIView programmatically in swift

Posted by: admin November 30, 2017 Leave a comment

Questions:

I have a UIView and and I have added tap gesture to it:

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

I am trying to call it programmatically in the testfile.

sendActionForEvent

I am using this function, but it is not working:

myView.sendActionForEvent(UIEvents.touchUpDown)

It shows unrecognised selector sent to instance.

How can I solve this problem?

Thanks in advance

Answers:

You need to initialize UITapGestureRecognizer with a target and action, like so:

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

Then, you should implement the handler, which will be called each time when a tap event occurs:

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

So now calling your tap gesture recognizer event handler is as easy as calling a method:

handleTap()

Questions:
Answers:

For anyone who is looking for Swift 3 solution

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
 func handleTap(_ sender: UITapGestureRecognizer) {
     print("Hello World")
  }

Questions:
Answers:

Just a note – Don’t forget to enabled interaction on the view:

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

view.addGestureRecognizer(tap)

// view.userInteractionEnabled = true

self.view.addSubview(view)

Questions:
Answers:

SWIFT 3.0 UITapGesture

STEP : 1

@IBOutlet var viewTap: UIView!

STEP : 2

var tapGesture = UITapGestureRecognizer()

STEP : 3

override func viewDidLoad() {
    super.viewDidLoad()
    // TAP Gesture
    tapGesture = UITapGestureRecognizer(target: self, action: #selector(ViewController.myviewTapped(_:)))
    tapGesture.numberOfTapsRequired = 1
    tapGesture.numberOfTouchesRequired = 1
    viewTap.addGestureRecognizer(tapGesture)
    viewTap.isUserInteractionEnabled = true
}

STEP : 4

func myviewTapped(_ sender: UITapGestureRecognizer) {

    if self.viewTap.backgroundColor == UIColor.yellow {
        self.viewTap.backgroundColor = UIColor.green
    }else{
        self.viewTap.backgroundColor = UIColor.yellow
    }
}

OUTPUT

enter image description here

Questions:
Answers:

This is how it works in Swift 3:

@IBOutlet var myView: UIView!
override func viewDidLoad() {
    super.viewDidLoad()

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

    myView.addGestureRecognizer(tap)
}

func handleTap() {
    print("tapped")
}

Questions:
Answers:

I worked out on Xcode 6.4 on swift. See below.

var view1: UIView!

func assignTapToView1() {          
  let tap = UITapGestureRecognizer(target: self, action: Selector("handleTap"))
  //  tap.delegate = self
  view1.addGestureRecognizer(tap)
  self.view .addSubview(view1)

...
}

func handleTap() {
 print("tap working")
 view1.removeFromSuperview()
 // view1.alpha = 0.1
}

Questions:
Answers:

Implementing tap gesture

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

Calls this function when the tap is recognized.

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

Update for For Swift 3

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

func touchHappen(_ sender: UITapGestureRecognizer) {
 print("Hello Museer")
}

Questions:
Answers:

For 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")
}

In Swift 4, you need to explicitly indicate that the triggered function is callable from Objective-C, so you need to add @objc too your handleTap function.

See @Ali Beadle ‘s answer here: Swift 4 add gesture: override vs @objc

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

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

Questions:
Answers:

You need to initialize UITapGestureRecognizer with a target and action, like so:

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

Then, you should implement the handler, which will be called each time when a tap event occurs:

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

Questions:
Answers:

If you want Objective C code is given below,

UITapGestureRecognizer *gesRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)]; // Declare the Gesture.
gesRecognizer.delegate = self;
[yourView addGestureRecognizer:gesRecognizer]; // Add Gesture to your view.

// Declare the Gesture Recognizer handler method.

- (void)handleTap:(UITapGestureRecognizer *)gestureRecognizer{
   NSLog(@"Tapped");
}

or you want swift code is given below,

import UIKit
class ViewController: UIViewController {

    @IBOutlet weak var myView: UIView!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Add tap gesture recognizer to view
        let tapGesture = UITapGestureRecognizer(target: self, action: Selector("handleTap:"))
        myView.addGestureRecognizer(tapGesture)
    }

    // this method is called when a tap is recognized
    func handleTap(sender: UITapGestureRecognizer) {

        print("tap")
    }
}

Questions:
Answers:

Try the following swift code (tested in Xcode 6.3.1):

    import UIKit

    class KEUITapGesture150427 : UIViewController {
      var _myTap: UITapGestureRecognizer?
      var _myView: UIView?

      override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = UIColor.whiteColor();

        _myTap = UITapGestureRecognizer(target: self
, action: Selector("_myHandleTap:"))
        _myTap!.numberOfTapsRequired = 1

        _myView = UIView(frame: CGRectMake(100, 200, 100, 100))
        _myView!.backgroundColor=UIColor.blueColor()
        _myView!.layer.cornerRadius = 20
        _myView!.layer.borderWidth = 1
        _myView!.addGestureRecognizer(_myTap!)
        view.addSubview(_myView!)
      }

      func _myHandleTap(sender: UITapGestureRecognizer) {
        if sender.state == .Ended {
          println("_myHandleTap(sender.state == .Ended)")
          sender.view!.backgroundColor
          = UIColor(red: CGFloat(drand48()), green: CGFloat(drand48()), blue: CGFloat(drand48()), alpha: 1.0);
        }
      }
    }

Note that your target could be any subclass of UIResponder, see (tested in Xcode 6.3.1):

    import UIKit

    class MyTapTarget  : UIResponder {
      func _myHandleTap2(sender: UITapGestureRecognizer) {
        if sender.state == .Ended {
          println("_myHandleTap2(sender.state == .Ended)")
          sender.view!.backgroundColor
            = UIColor(red: CGFloat(drand48()), green: CGFloat(drand48()), blue: CGFloat(drand48()), alpha: 1.0);
        }
      }
    }

    class KEUITapGesture150427b : UIViewController {
      var _myTap: UITapGestureRecognizer?
      var _myView: UIView?
      var _myTapTarget: MyTapTarget?

      override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = UIColor.whiteColor();

        _myTapTarget = MyTapTarget()
        _myTap = UITapGestureRecognizer(target: _myTapTarget!
, action: Selector("_myHandleTap2:"))
        _myTap!.numberOfTapsRequired = 1

        _myView = UIView(frame: CGRectMake(100, 200, 100, 100))
        _myView!.backgroundColor=UIColor.blueColor()
        _myView!.layer.cornerRadius = 20
        _myView!.layer.borderWidth = 1
        _myView!.addGestureRecognizer(_myTap!)
        view.addSubview(_myView!)
      }
    }

Questions:
Answers:

I worked out on Xcode 7.3.1 on Swift 2.2. See below.

func addTapGesture() {
    let tap = UITapGestureRecognizer(target: self, action: #selector(MyViewController.handleTap))
    tap.numberOfTapsRequired = 1
    self.myView.addGestureRecognizer(tap)
}

func handleTap() {
    // Your code here...
}

Questions:
Answers:

Instead of invoking myView’s UITapGestureRecognizer, you can directly call the handleTap function,