How to add a touch event to a UIView?

Question

How do I add a touch event to a UIView?
I try:

UIView *headerView = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, tableView.bounds.size.width, nextY)] autorelease];
[headerView addTarget:self action:@selector(myEvent:) forControlEvents:UIControlEventTouchDown];
// ERROR MESSAGE: UIView may not respond to '-addTarget:action:forControlEvents:'

I don't want to create a subclass and overwrite

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

Solution 1

In iOS 3.2 and higher, you can use gesture recognizers. For example, this is how you would handle a tap event:

//The setup code (in viewDidLoad in your view controller)
UITapGestureRecognizer *singleFingerTap = 
  [[UITapGestureRecognizer alloc] initWithTarget:self 
                                          action:@selector(handleSingleTap:)];
[self.view addGestureRecognizer:singleFingerTap];

//The event handling method
- (void)handleSingleTap:(UITapGestureRecognizer *)recognizer
{
  CGPoint location = [recognizer locationInView:[recognizer.view superview]];

  //Do stuff here...
}

There are a bunch of built in gestures as well. Check out the docs for iOS event handling and UIGestureRecognizer. I also have a bunch of sample code up on github that might help.

Solution 2

Gesture Recognizers

There are a number of commonly used touch events (or gestures) that you can be notified of when you add a Gesture Recognizer to your view. They following gesture types are supported by default:

• UITapGestureRecognizer Tap (touching the screen briefly one or more times)
• UILongPressGestureRecognizer Long touch (touching the screen for a long time)
• UIPanGestureRecognizer Pan (moving your finger across the screen)
• UISwipeGestureRecognizer Swipe (moving finger quickly)
• UIPinchGestureRecognizer Pinch (moving two fingers together or apart - usually to zoom)
• UIRotationGestureRecognizer Rotate (moving two fingers in a circular direction)

In addition to these, you can also make your own custom gesture recognizer.

Adding a Gesture in the Interface Builder

Drag a gesture recognizer from the object library onto your view.

Control drag from the gesture in the Document Outline to your View Controller code in order to make an Outlet and an Action.

This should be set by default, but also make sure that User Action Enabled is set to true for your view.

Adding a Gesture Programmatically

To add a gesture programmatically, you (1) create a gesture recognizer, (2) add it to a view, and (3) make a method that is called when the gesture is recognized.

import UIKit
class ViewController: UIViewController {

    @IBOutlet weak var myView: UIView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 1. create a gesture recognizer (tap gesture)
        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleTap(sender:)))
        
        // 2. add the gesture recognizer to a view
        myView.addGestureRecognizer(tapGesture)
    }
    
    // 3. this method is called when a tap is recognized
    @objc func handleTap(sender: UITapGestureRecognizer) {
        print("tap")
    }
}

Notes

• The sender parameter is optional. If you don't need a reference to the gesture then you can leave it out. If you do so, though, remove the (sender:) after the action method name.
• The naming of the handleTap method was arbitrary. Name it whatever you want using action: #selector(someMethodName(sender:)).

More Examples

You can study the gesture recognizers that I added to these views to see how they work.

Here is the code for that project:

import UIKit
class ViewController: UIViewController {
    
    @IBOutlet weak var tapView: UIView!
    @IBOutlet weak var doubleTapView: UIView!
    @IBOutlet weak var longPressView: UIView!
    @IBOutlet weak var panView: UIView!
    @IBOutlet weak var swipeView: UIView!
    @IBOutlet weak var pinchView: UIView!
    @IBOutlet weak var rotateView: UIView!
    @IBOutlet weak var label: UILabel!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Tap
        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleTap))
        tapView.addGestureRecognizer(tapGesture)
        
        // Double Tap
        let doubleTapGesture = UITapGestureRecognizer(target: self, action: #selector(handleDoubleTap))
        doubleTapGesture.numberOfTapsRequired = 2
        doubleTapView.addGestureRecognizer(doubleTapGesture)
        
        // Long Press
        let longPressGesture = UILongPressGestureRecognizer(target: self, action: #selector(handleLongPress(gesture:)))
        longPressView.addGestureRecognizer(longPressGesture)
        
        // Pan
        let panGesture = UIPanGestureRecognizer(target: self, action: #selector(handlePan(gesture:)))
        panView.addGestureRecognizer(panGesture)
        
        // Swipe (right and left)
        let swipeRightGesture = UISwipeGestureRecognizer(target: self, action: #selector(handleSwipe(gesture:)))
        let swipeLeftGesture = UISwipeGestureRecognizer(target: self, action: #selector(handleSwipe(gesture:)))
        swipeRightGesture.direction = UISwipeGestureRecognizerDirection.right
        swipeLeftGesture.direction = UISwipeGestureRecognizerDirection.left
        swipeView.addGestureRecognizer(swipeRightGesture)
        swipeView.addGestureRecognizer(swipeLeftGesture)
        
        // Pinch
        let pinchGesture = UIPinchGestureRecognizer(target: self, action: #selector(handlePinch(gesture:)))
        pinchView.addGestureRecognizer(pinchGesture)
        
        // Rotate
        let rotateGesture = UIRotationGestureRecognizer(target: self, action: #selector(handleRotate(gesture:)))
        rotateView.addGestureRecognizer(rotateGesture)
        
    }
    
    // Tap action
    @objc func handleTap() {
        label.text = "Tap recognized"
        
        // example task: change background color
        if tapView.backgroundColor == UIColor.blue {
            tapView.backgroundColor = UIColor.red
        } else {
            tapView.backgroundColor = UIColor.blue
        }
        
    }
    
    // Double tap action
    @objc func handleDoubleTap() {
        label.text = "Double tap recognized"
        
        // example task: change background color
        if doubleTapView.backgroundColor == UIColor.yellow {
            doubleTapView.backgroundColor = UIColor.green
        } else {
            doubleTapView.backgroundColor = UIColor.yellow
        }
    }
    
    // Long press action
    @objc func handleLongPress(gesture: UILongPressGestureRecognizer) {
        label.text = "Long press recognized"
        
        // example task: show an alert
        if gesture.state == UIGestureRecognizerState.began {
            let alert = UIAlertController(title: "Long Press", message: "Can I help you?", preferredStyle: UIAlertControllerStyle.alert)
            alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
            self.present(alert, animated: true, completion: nil)
        }
    }
    
    // Pan action
    @objc func handlePan(gesture: UIPanGestureRecognizer) {
        label.text = "Pan recognized"
        
        // example task: drag view
        let location = gesture.location(in: view) // root view
        panView.center = location
    }
    
    // Swipe action
    @objc func handleSwipe(gesture: UISwipeGestureRecognizer) {
        label.text = "Swipe recognized"
        
        // example task: animate view off screen
        let originalLocation = swipeView.center
        if gesture.direction == UISwipeGestureRecognizerDirection.right {
            UIView.animate(withDuration: 0.5, animations: {
                self.swipeView.center.x += self.view.bounds.width
            }, completion: { (value: Bool) in
                self.swipeView.center = originalLocation
            })
        } else if gesture.direction == UISwipeGestureRecognizerDirection.left {
            UIView.animate(withDuration: 0.5, animations: {
                self.swipeView.center.x -= self.view.bounds.width
            }, completion: { (value: Bool) in
                self.swipeView.center = originalLocation
            })
        }
    }
    
    // Pinch action
    @objc func handlePinch(gesture: UIPinchGestureRecognizer) {
        label.text = "Pinch recognized"
        
        if gesture.state == UIGestureRecognizerState.changed {
            let transform = CGAffineTransform(scaleX: gesture.scale, y: gesture.scale)
            pinchView.transform = transform
        }
    }
    
    // Rotate action
    @objc func handleRotate(gesture: UIRotationGestureRecognizer) {
        label.text = "Rotate recognized"
        
        if gesture.state == UIGestureRecognizerState.changed {
            let transform = CGAffineTransform(rotationAngle: gesture.rotation)
            rotateView.transform = transform
        }
    }
}

Notes

• You can add multiple gesture recognizers to a single view. For the sake of simplicity, though, I didn't do that (except for the swipe gesture). If you need to for your project, you should read the gesture recognizer documentation. It is fairly understandable and helpful.
• Known issues with my examples above: (1) Pan view resets its frame on next gesture event. (2) Swipe view comes from the wrong direction on the first swipe. (These bugs in my examples should not affect your understanding of how Gestures Recognizers work, though.)

Solution 3

I think you can simply use

UIControl *headerView = ...
[headerView addTarget:self action:@selector(myEvent:) forControlEvents:UIControlEventTouchDown];

i mean headerView extends from UIControl.

Solution 4

Swift 3 & Swift 4

import UIKit

extension UIView {
  func addTapGesture(tapNumber: Int, target: Any, action: Selector) {
    let tap = UITapGestureRecognizer(target: target, action: action)
    tap.numberOfTapsRequired = tapNumber
    addGestureRecognizer(tap)
    isUserInteractionEnabled = true
  }
}

Use

yourView.addTapGesture(tapNumber: 1, target: self, action: #selector(yourMethod))

Solution 5

Based on the accepted answer you can define a macro:

#define handle_tap(view, delegate, selector) do {\
    view.userInteractionEnabled = YES;\
    [view addGestureRecognizer: [[UITapGestureRecognizer alloc] initWithTarget:delegate action:selector]];\
} while(0)

This macro uses ARC, so there's no release call.

Macro usage example:

handle_tap(userpic, self, @selector(onTapUserpic:));

View more solutions

Comments

[Mr.Javed Multani]

For swift you can get it from here: stackoverflow.com/questions/28675209/…

[M Penades]

But that is overwriting touch defautlt action of the view. ¿Is it possible to call default touch action of the view? Something like [super touchesBegan] ?...

[zakdances]

What does the CGPoint line do?

[Nathan Eror]

@yourfriendzak the CGPoint represents the location of the tap in the superview of the tapped view. You can use this point to move the tapped view (or a sibling view) to the tapped location. This is more useful in the handler for a UIPanGestureRecognizer for dragging the view around the screen.

[natbro]

great concise answer, thanks. but sheesh, wouldn't it be nice if this were a wee bit easier?! :)

[Nathan Eror]

It's not too bad, but I wish there were a block based API like github.com/neror/ftutils/blob/master/Headers/FTUtils/…. Xcode 4 does have support for adding/configuring gesture recognizers in Interface Builder, too.

[David T.]

I got most of this to work; however, why is it that when i print the coordinates using NSLog(@"touched points: %f, %f", location.x, location.y); i always get 0.00000, 0.00000 ??? is it because of my simulator? i'm using my trackpad on my mac pro

[meadlai]

@NathanEror UIView only can add ONE GestureRecognizer. I try to handle more than one EventHandler. gist.github.com/1450404

[ohho]

This is the better answer. UITapGestureRecognizer is not a replacement of UIControlEventTouchDown. A Tap usually composes of UIControlEventTouchDown and UIControlEventTouchUpInside.

[RobertJoseph]

A UIView is not a UIControl and thus does not have access to addTarget:action:forControlEvents:.

[pretzels1337]

Also note that a UIControl inherits from UIView. For my purposes all I had to do was a simple switch of subclass type.

[david]

If you create the view in storyboard, don't forget to enable the "user interaction enabled" option.

[Zar E Ahmer]

you can set its class to UIControl @RobertJoseph .. Go to xib file and set the View Custom class to UIControl . now you can handle event in it..

[Zar E Ahmer]

where we should define macros in .h or .m and what should be the name of the parameters . i mean #define handle_tap(UIView view,Delegate delegate , SEL selector)do..

[Anthony Glyadchenko]

So why this a better solution again since I'm changing inheritance just to handle taps?

[Moin Shirazi]

i am having multiple view so can i can the sender id ??

[Programming Learner]

You have to go to the inner subview, then you can paas the sender.---------for (UIView *view in self.topicScrollView.subviews) {//Go Inside the superview if ([view isKindOfClass:[UIButton class]]) { // Go to that particular view // Here you have reached upto that point. } }

[dollar2048]

you have to add view.userInteractionEnabled = YES;

[He Yifei 何一非]

what is BlockTap?

[Esqarrouth]

Oh man, forgot that part. Its a custom function. Here: github.com/goktugyil/EZSwiftExtensions/blob/master/Sources/…

[Er. Vihar]

Your answer is really nice and helpful with detailed description. And thats why I have up vote you answer also. But you just missed one instruction which I think you must include in your answer as you have explained it in full detail. That instruction is about setting "<yourView>.EnableUserInteraction = TRUE". I hope you agree with me.

[sebesbal]

There is a difference between a single tap, and a touch event, with multiple pointers and down/move/up states. Almost each of the answers talks about single tap...

[Mikrasya]

Thanks. Works great!

[budiDino]

Love this! Adding to all of the projects ;)

[neiker]

In order to make this work on a UIView you need to also add: self.isUserInteractionEnabled = true;

[janakmshah]

@AnthonyGlyadchenko this is a better answer because the original question asks: How do I add a touch event to a UIView? It isn't asking for a tap event. Specifically OP wants to implement UIControlEventTouchDown. Switching the UIView to UIControl is the right answer because Gesture Recognisers don't know anything about .touchDown, .touchUpInside, .touchUpOutside etc.

[Muhammad Ahmed]

I have view in which i have implemented DropMenu whenever a view is tapped. i am getting an error "Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value" at myView.addGestureRecognizer(tapGesture) when ever i go to next screen