How to Add a Touch Event to a Uiview

How to add a touch event to a UIView?

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.

UIView touch event in controller

You will have to add it through code. First, create the view and add it to the hierarchy:

var myView = UIView(frame: CGRectMake(100, 100, 100, 100))
self.view.addSubview(myView) 

After that initialize gesture recognizer. Until Swift 2:

let gesture = UITapGestureRecognizer(target: self, action: "someAction:")

After Swift 2:

let gesture = UITapGestureRecognizer(target: self, action:  #selector (self.someAction (_:)))

Then bind it to the view:

self.myView.addGestureRecognizer(gesture)

    

Swift 3:

func someAction(_ sender:UITapGestureRecognizer){     
  // do other task
}
    

Swift 4 just add @objc before func:

@objc func someAction(_ sender:UITapGestureRecognizer){     
    // do other task
}

Swift UI:

Text("Tap me!").tapAction {
    print("Tapped!")
}

How to send touch event to a UIView on iOS

UIButton *btnInPicker = nil;
for( UIView *_subView in self.broadcastPicker.subviews) {
    if( [_subView isKindOfClass:[UIButton class]] ) {
        btnInPicker = (UIButton *)_subView;
        break;
    }
}


if(btnInPicker) {
    [btnInPicker sendActionsForControlEvents:UIControlEventTouchDown];
}

but it has a issue:
Unbalanced calls to begin/end appearance transitions for

Touch Event on UIView

A very general way to get touches is to override these methods in a custom UIView subclass:

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event

The official docs for these methods is under Responding to Touch Events in the UIResponder class docs (UIView inherits those methods since it's a subclass of UIResponder). Longer and more introductory docs can be found in the Event Handling Guide for iOS.

If you just want to detect a tap (touch-down, then touch-up within your view), it's easiest to add a UIButton as a subview of your view, and add your own custom method as a target/action pair for that button. Custom buttons are invisible by default, so it wouldn't affect the look of your view.

If you're looking for more advanced interactions, it's also good to know about the UIGestureRecognizer class.

How to add touch event for custom UIControl and determine the touched item in swift 5

First of all, all interactions with UILabel are disabled by default. To change it, set isUserInteractionEnabled to true.

import UIKit

@IBDesignable
class SomeUI: UIControl {

    private var componentsAdded = false
    let labelOne = UILabel()
    private let labelTwo = UILabel()

    required init?(coder: NSCoder) {
        super.init(coder: coder)
        labelOne.isUserInteractionEnabled = true
    }

    override func draw(_ rect: CGRect) {
        if !componentsAdded {
            componentsAdded = true
            self.addSubview(labelOne)
            labelOne.text = "one"
            labelOne.sizeToFit()
            self.addSubview(labelTwo)
            labelTwo.text = "two"
            labelTwo.sizeToFit()
        }
        labelOne.center = CGPoint(x: 10, y: 10)
        labelTwo.center = CGPoint(x: 10, y: 40)
    }
}



\\ File: ViewController.swift
    import UIKit

    class ViewController: UIViewController {

        override func viewDidLoad() {
            super.viewDidLoad()
            // Do any additional setup after loading the view.
        }

        @IBOutlet weak var someLabel: UILabel!
        @IBOutlet weak var sui: SomeUI!

        @IBAction func changeLabel(_ gestureRecognizer: UITapGestureRecognizer) {
            let view = gestureRecognizer.view
            let loc = gestureRecognizer.location(in: view)
            let subview = sui.hitTest(loc, with: nil)

            switch subview {
            case sui.labelOne: print("1") someLabel.text = "label one tapped"
            case sui.labelTwo: print("2") someLabel.text = "label two tapped"
            default: print("0") someLabel.text = "TAPPIO?" }
        }
    }

In Storyboard add a Tap Gesture Recognizer and set its "Sent Actions" to "changeLabel", "Referencing outlet collections" to your custom SomeUI IBOutlet referenced here by "sui" property

@IBOutlet weak var sui: SomeUI!

Touch Event on UIView

A very general way to get touches is to override these methods in a custom UIView subclass:

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event

The official docs for these methods is under Responding to Touch Events in the UIResponder class docs (UIView inherits those methods since it's a subclass of UIResponder). Longer and more introductory docs can be found in the Event Handling Guide for iOS.

If you just want to detect a tap (touch-down, then touch-up within your view), it's easiest to add a UIButton as a subview of your view, and add your own custom method as a target/action pair for that button. Custom buttons are invisible by default, so it wouldn't affect the look of your view.

If you're looking for more advanced interactions, it's also good to know about the UIGestureRecognizer class.

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