By Benr783


2014-06-08 01:26:02 8 Comments

I am trying to build UI's programmatically. How do I get this action working? I am developing with Swift.

Code in viewDidLoad:

override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        let myFirstLabel = UILabel()
        let myFirstButton = UIButton()
        myFirstLabel.text = "I made a label on the screen #toogood4you"
        myFirstLabel.font = UIFont(name: "MarkerFelt-Thin", size: 45)
        myFirstLabel.textColor = UIColor.redColor()
        myFirstLabel.textAlignment = .Center
        myFirstLabel.numberOfLines = 5
        myFirstLabel.frame = CGRectMake(15, 54, 300, 500)
        myFirstButton.setTitle("✸", forState: .Normal)
        myFirstButton.setTitleColor(UIColor.blueColor(), forState: .Normal)
        myFirstButton.frame = CGRectMake(15, -50, 300, 500)
        myFirstButton.addTarget(self, action: "pressed", forControlEvents: .TouchUpInside)
        self.view.addSubview(myFirstLabel)
        self.view.addSubview(myFirstButton)
    }

        func pressed(sender: UIButton!) {
            var alertView = UIAlertView();
            alertView.addButtonWithTitle("Ok");
            alertView.title = "title";
            alertView.message = "message";
            alertView.show();
        }

18 comments

@JP Aquino 2016-10-31 21:34:42

Swift 3/4

//Create button

let button = UIButton(frame: CGRect(x: 20, y: 20, width: 200, height: 60))
 button.setTitle("Email", for: .normal)
 button.backgroundColor = .white
 button.setTitleColor(UIColor.black, for: .normal)
 button.addTarget(self, action: #selector(self.buttonTapped), for: .touchUpInside)
 myView.addSubview(button)



@objc func buttonTapped(sender : UIButton) {
                //Write button action here
            }

@iOS 2019-01-11 12:09:18

In iOS 12, Swift 4.2 & XCode 10.1

//For system type button
let button = UIButton(type: .system)
button.frame = CGRect(x: 100, y: 250, width: 100, height: 50)
//        button.backgroundColor = .blue
button.setTitle("Button", for: .normal)
button.setTitleColor(.white, for: .normal)
button.titleLabel?.font = UIFont.boldSystemFont(ofSize: 13.0)
button.titleLabel?.textAlignment = .center//Text alighment center
button.titleLabel?.numberOfLines = 0//To display multiple lines in UIButton
button.titleLabel?.lineBreakMode = .byWordWrapping//By word wrapping
button.tag = 1//To assign tag value
button.btnProperties()//Call UIButton properties from extension function
button.addTarget(self, action:#selector(self.buttonClicked), for: .touchUpInside)
self.view.addSubview(button)

//For custom type button (add image to your button)
let button2 = UIButton(type: .custom)
button2.frame = CGRect(x: 100, y: 400, width: 100, height: 50)
//        button2.backgroundColor = .blue
button2.setImage(UIImage.init(named: "img.png"), for: .normal)
button2.tag = 2
button2.btnProperties()//Call UIButton properties from extension function
button2.addTarget(self, action:#selector(self.buttonClicked), for: .touchUpInside)
self.view.addSubview(button2)

@objc func buttonClicked(sender:UIButton) {
    print("Button \(sender.tag) clicked")
}

//You can add UIButton properties like this also
extension UIButton {
    func btnProperties() {
        layer.cornerRadius = 10//Set button corner radious
        clipsToBounds = true
        backgroundColor = .blue//Set background colour
        //titleLabel?.textAlignment = .center//add properties like this
    }
}

@Saranjith 2019-01-17 10:31:44

Swift 4.2 - XCode 10.1

Using a closure

let button: UIButton = {
  let button = UIButton(type: .system)
  button.titleLabel?.font = UIFont.systemFont(ofSize: 20)
  ...
  return button
}()

@n.by.n 2016-03-30 12:15:43

Swift 2.2 Xcode 7.3

Since Objective-C String Literals are deprecated now for button callback methods

let button:UIButton = UIButton(frame: CGRectMake(100, 400, 100, 50))
button.backgroundColor = UIColor.blackColor()
button.setTitle("Button", forState: UIControlState.Normal)
button.addTarget(self, action:#selector(self.buttonClicked), forControlEvents: .TouchUpInside)
self.view.addSubview(button)

func buttonClicked() {
     print("Button Clicked")
}

Swift 3 Xcode 8

let button:UIButton = UIButton(frame: CGRect(x: 100, y: 400, width: 100, height: 50))
button.backgroundColor = .black
button.setTitle("Button", for: .normal)
button.addTarget(self, action:#selector(self.buttonClicked), for: .touchUpInside)
self.view.addSubview(button)

func buttonClicked() {
    print("Button Clicked")
}

Swift 4 Xcode 9

let button:UIButton = UIButton(frame: CGRect(x: 100, y: 400, width: 100, height: 50))
button.backgroundColor = .black
button.setTitle("Button", for: .normal)
button.addTarget(self, action:#selector(self.buttonClicked), for: .touchUpInside)
self.view.addSubview(button)

@objc func buttonClicked() {
    print("Button Clicked")
}

@ArgaPK 2018-01-09 13:31:31

@n.by.n how to pass argument on this method buttonClicked()?

@Tyler 2018-01-30 22:36:44

If you go into the Main storyboard part, and in the bottom right go to the circle with a square, and use a blank button. Then in the code use @IBAction with it to get it wired in. Then you can make a @IBAction function with it.

@Ted van Gaalen 2018-01-01 18:28:07

Swift "Button factory" extension for UIButton (and while we're at it) also for UILabel like so:

extension UILabel
{
// A simple UILabel factory function
// returns instance of itself configured with the given parameters

// use example (in a UIView or any other class that inherits from UIView):

//   addSubview(   UILabel().make(     x: 0, y: 0, w: 100, h: 30,
//                                   txt: "Hello World!",
//                                 align: .center,
//                                   fnt: aUIFont,
//                              fntColor: UIColor.red)                 )
//

func make(x: CGFloat, y: CGFloat, w: CGFloat, h: CGFloat,
          txt: String,
          align: NSTextAlignment,
          fnt: UIFont,
          fntColor: UIColor)-> UILabel
{
    frame = CGRect(x: x, y: y, width: w, height: h)
    adjustsFontSizeToFitWidth = true
    textAlignment = align
    text = txt
    textColor = fntColor
    font = fnt
    return self
}
// Of course, you can make more advanced factory functions etc.
// Also one could subclass UILabel, but this seems to be a     convenient case for an extension.
}


extension UIButton
{
// UIButton factory returns instance of UIButton
//usage example:

// addSubview(UIButton().make(x: btnx, y:100, w: btnw, h: btnh,
// title: "play", backColor: .red,
// target: self,
// touchDown: #selector(play), touchUp: #selector(stopPlay)))


func make(   x: CGFloat,y: CGFloat,
             w: CGFloat,h: CGFloat,
                  title: String, backColor: UIColor,
                  target: UIView,
                  touchDown:  Selector,
                  touchUp:    Selector ) -> UIButton
{
    frame = CGRect(x: x, y: y, width: w, height: h)
    backgroundColor = backColor
    setTitle(title, for: .normal)
    addTarget(target, action: touchDown, for: .touchDown)
    addTarget(target, action: touchUp  , for: .touchUpInside)
    addTarget(target, action: touchUp  , for: .touchUpOutside)

    return self
}
}

Tested in Swift in Xcode Version 9.2 (9C40b) Swift 4.x

@Dash 2014-06-08 01:27:15

You're just missing the colon at the end of the selector name. Since pressed takes a parameter the colon must be there. Also your pressed function shouldn't be nested inside viewDidLoad.

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    let myFirstLabel = UILabel()
    let myFirstButton = UIButton()
    myFirstLabel.text = "I made a label on the screen #toogood4you"
    myFirstLabel.font = UIFont(name: "MarkerFelt-Thin", size: 45)
    myFirstLabel.textColor = UIColor.redColor()
    myFirstLabel.textAlignment = .Center
    myFirstLabel.numberOfLines = 5
    myFirstLabel.frame = CGRectMake(15, 54, 300, 500)
    myFirstButton.setTitle("✸", forState: .Normal)
    myFirstButton.setTitleColor(UIColor.blueColor(), forState: .Normal)
    myFirstButton.frame = CGRectMake(15, -50, 300, 500)
    myFirstButton.addTarget(self, action: #selector(myClass.pressed(_:)), forControlEvents: .TouchUpInside)
    self.view.addSubview(myFirstLabel)
    self.view.addSubview(myFirstButton)
}

@objc func pressed(sender: UIButton!) {
    var alertView = UIAlertView()
    alertView.addButtonWithTitle("Ok")
    alertView.title = "title"
    alertView.message = "message"
    alertView.show()
}

EDIT: Updated to reflect best practices in Swift 2.2. #selector() should be used rather than a literal string which is deprecated.

@Benr783 2014-06-08 01:29:41

The app still crashes when I press the button.

@Dash 2014-06-08 01:30:20

Sorry fixed. The function shouldn't be nested.

@juniorgarcia 2015-03-06 14:30:01

Hey, can you tell me the logic behind the colon we need to add after the string that represents the action?

@HughHughTeotl 2015-07-09 12:44:58

@chorajunior The colon is needed because the pressed function takes an argument.

@Dave G 2015-09-02 03:29:26

Inversely, anyone reading this may also want to know that if your button action references a function that takes no parameter, the colon is not needed and may even cause an error if not removed.

@Felipe 2015-10-27 18:14:21

Thanks, m8! Starting up with Swift today so everything is kind of strange (:

@Arbel Israeli 2015-11-20 16:15:56

Colon only in functions that take only 1 parameter.

@evanflash 2016-01-07 16:03:33

It's worth noting that the pressed function needs to be public, at least that has been my experience.

@evanflash 2016-01-07 16:09:50

whoops, too late to edit my comment, but here's some more clarification about access control using addTarget stackoverflow.com/questions/25056278/…

@corykon 2016-02-12 23:31:54

After following everything described above I kept getting the unrecognized selector crash. Found the answerI needed here: stackoverflow.com/a/29409052/2311702

@Raman 2017-09-01 08:11:00

Swift 4

    private func createButton {
        let sayButtonT = UIButton(type: .custom)
        sayButtonT.addTarget(self, action: #selector(sayAction(_:)), for: .touchUpInside)
    }

    @objc private func sayAction(_ sender: UIButton?) {

    }

@Rex 2017-08-29 05:12:00

Using this in Objective-C

UIButton *testButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[testButton setTitle:@"Go to here" forState:UIControlStateNormal];
testButton.frame = CGRectMake(20, 20, 150, 150);    
[self.view addSubview:testButton];

Using this in Latest Swift

let testButton   = UIButton(type: UIButtonType.system) as UIButton
testButton.frame = CGRectMake(160, 160, 80, 20)
testButton.backgroundColor = UIColor.green
testButton.setTitle("Button testing:- ", forState: UIControlState.normal)
self.view.addSubview(testButton)

@samatron 2014-07-23 23:05:02

You should be able to create a customize UI button programmatically by accessing the titleLabel property of UIButton.

Per Class Reference in Swift: Regarding the titleLabel property, it says that "although this property is read-only, its own properties are read/write. Use these properties primarily to configure the text of the button."

In Swift, you can directly modify the properties of titleLabel like such:

let myFirstButton = UIButton()
myFirstButton.titleLabel!.text = "I made a label on the screen #toogood4you"
myFirstButton.titleLabel!.font = UIFont(name: "MarkerFelt-Thin", size: 45)
myFirstButton.titleLabel!.textColor = UIColor.red
myFirstButton.titleLabel!.textAlignment = .center
myFirstButton.titleLabel!.numberOfLines = 5
myFirstButton.titleLabel!.frame = CGRect(x: 15, y: 54, width: 300, height: 500)

Edit

Swift 3.1 Syntax

@user2202911 2015-01-20 21:16:48

i tried running this code and it is not working for me. Non of the chidlren of titleLabel seem to exist

@phitsch 2016-11-19 12:57:22

Swift 3: You can create a UIButton programmatically

either inside a methods scope for example in ViewDidLoad() Be sure to add constraints to the button, otherwise you wont see it

let button = UIButton()
button.translatesAutoresizingMaskIntoConstraints = false
button.target(forAction: #selector(buttonAction), withSender: self)
//button.backgroundColor etc

view.addSubview(button)

func buttonAction() {
   //some Action
}

or outside your scope as global variable to access it from anywhere in your module

let button: UIButton = {
   let b = UIButton()
   b.translatesAutoresizingMaskIntoConstraints = false
   //b.backgroundColor etc
   return b
}()

and then you setup the constraints

func setupButtonView() {
   view.addSubview(button)
   button.widthAnchor.constraint(equalToConstant: 40).isActive = true
   button.heightAnchor.constraint(equalToConstant: 40).isActive = true
   // etc

}

@emraz 2016-09-22 07:35:04

For Swift 3 Xcode 8.......

let button = UIButton(frame: CGRect(x: 0, y: 0, width: container.width, height: container.height))
        button.addTarget(self, action: #selector(self.barItemTapped), for: .touchUpInside)


func barItemTapped(sender : UIButton) {
    //Write button action here
}

@onCompletion 2015-07-21 17:07:12

In Swift We Can Make A button programmatically by writing this code in our viewcontroller.swift file...

import UIKit

class ViewController: UIViewController
{  
private let firstbutton:UIButton = UIButton()

override func viewDidLoad() {
    super.viewDidLoad()
    self.firstbutton = UIButton.buttonWithType(UIButtonType.Custom) as? UIButton
    self.firstbutton!.frame = CGRectMake(100, 200, 100, 100)
    self.firstbutton!.backgroundColor = UIColor.redColor()
    self.firstbutton!.setTitle("My Button", forState: UIControlState.Normal)
    self.firstbutton!.addTarget(self, action:#selector(self.firstButtonClicked), forControlEvents: .TouchUpInside)
    self.view.addSubview(firstbutton!)
    }

func firstButtonClicked(){
   print("First Button Clicked")
}

@Ananthu R Krishnan 2016-08-01 14:15:34

Swift: Ui Button create programmatically,

var button: UIButton = UIButton(type: .Custom)

button.frame = CGRectMake(80.0, 210.0, 160.0, 40.0)

button.addTarget(self, action: #selector(self.aMethod), forControlEvents: .TouchUpInside)

button.tag=2

button.setTitle("Hallo World", forState: .Normal)

view.addSubview(button)


func aMethod(sender: AnyObject) {
    print("you clicked on button \(sender.tag)")
}

@7stud 2016-01-09 15:17:02

UIButton with constraints in iOS 9.1/Xcode 7.1.1/Swift 2.1:

import UIKit
import MapKit

class MapViewController: UIViewController {  

    override func loadView() {
        mapView = MKMapView()  //Create a view...
        view = mapView         //assign it to the ViewController's (inherited) view property.
                               //Equivalent to self.view = mapView

        myButton = UIButton(type: .RoundedRect)  //RoundedRect is an alias for System (tested by printing out their rawValue's)
        //myButton.frame = CGRect(x:50, y:500, width:70, height:50)  //Doesn't seem to be necessary when using constraints.
        myButton.setTitle("Current\nLocation", forState: .Normal)
        myButton.titleLabel?.lineBreakMode = .ByWordWrapping  //If newline in title, split title onto multiple lines
        myButton.titleLabel?.textAlignment = .Center
        myButton.setTitleColor(UIColor.whiteColor(), forState: .Normal)
        myButton.layer.cornerRadius = 6   //For some reason, a button with type RoundedRect has square corners
        myButton.backgroundColor = UIColor.redColor().colorWithAlphaComponent(0.5) //Make the color partially transparent
        //Attempt to add padding around text. Shrunk the frame when I tried it.  Negative values had no effect.
        //myButton.titleEdgeInsets = UIEdgeInsetsMake(-10,-10,-10,-10)
        myButton.contentEdgeInsets = UIEdgeInsetsMake(5,5,5,5)  //Add padding around text.

        myButton.addTarget(self, action: "getCurrentLocation:", forControlEvents: .TouchUpInside)
        mapView.addSubview(myButton)

        //Button Constraints:
        myButton.translatesAutoresizingMaskIntoConstraints = false //***
        //bottomLayoutGuide(for tab bar) and topLayoutGuide(for status bar) are properties of the ViewController
        //To anchor above the tab bar on the bottom of the screen:
        let bottomButtonConstraint = myButton.bottomAnchor.constraintEqualToAnchor(bottomLayoutGuide.topAnchor, constant: -20) //Implied call of self.bottomLayoutGuide. Anchor 20 points **above** the top of the tab bar.
        //To anchor to the blue guide line that is inset from the left 
        //edge of the screen in InterfaceBuilder:
        let margins = view.layoutMarginsGuide  //Now the guide is a property of the View.
        let leadingButtonConstraint = myButton.leadingAnchor.constraintEqualToAnchor(margins.leadingAnchor)

        bottomButtonConstraint.active = true
        leadingButtonConstraint.active = true
    }


    func getCurrentLocation(sender: UIButton) {
        print("Current Location button clicked!")
    }

The button is anchored to the bottom left corner, above the tab bar.

@nyxee 2017-05-23 09:23:11

how does getCurrentLocation help us to get the location please?

@7stud 2017-05-23 19:34:42

@nyxee, The question here was about how to programmatically make a button. Getting the location of a user has nothing to do with making a button. To get a user's location see here; developer.apple.com/reference/corelocation/cllocationmanager‌​. If you can’t figure it out, ask your own question please.

@krushnsinh 2015-08-25 12:26:35

try these..i hope it helps...

override func viewDidLoad() {
super.viewDidLoad()  

    let btn = UIButton()
    btn.frame = CGRectMake(10, 10, 50, 50)  //set frame
    btn.setTitle("btn", forState: .Normal)  //set button title
    btn.setTitleColor(UIColor.redColor(), forState: .Normal) //set button title color
    btn.backgroundColor = UIColor.greenColor() //set button background color
    btn.tag = 1 // set button tag
    btn.addTarget(self, action: "btnclicked:", forControlEvents: .TouchUpInside) //add button action
    self.view.addSubview(btn) //add button in view

}

these is buttons click event..

func btnclicked(sender: UIButton!) 
{
    //write the task you want to perform on buttons click event..
}

@Shanmugasundharam 2015-04-23 07:28:45

Swift: Ui Button create programmatically

let myButton = UIButton() 
myButton.titleLabel!.frame = CGRectMake(15, 54, 300, 500) 
myButton.titleLabel!.text = "Button Label"
myButton.titleLabel!.textColor = UIColor.redColor()
myButton.titleLabel!.textAlignment = .Center

@user1671097 2014-06-23 10:38:40

Yeah in simulator. Some times it wont recognise the selector there is a bug it seems. Even i faced not for your code , then i just changed the action name (selector). It works

let buttonPuzzle:UIButton = UIButton(frame: CGRectMake(100, 400, 100, 50))
buttonPuzzle.backgroundColor = UIColor.greenColor()
buttonPuzzle.setTitle("Puzzle", forState: UIControlState.Normal)
buttonPuzzle.addTarget(self, action: "buttonAction:", forControlEvents: UIControlEvents.TouchUpInside)
buttonPuzzle.tag = 22;
self.view.addSubview(buttonPuzzle)

An example selector function is here:

func buttonAction(sender:UIButton!) {
    var btnsendtag:UIButton = sender
    if btnsendtag.tag == 22 {            
        //println("Button tapped tag 22")
    }
}

Related Questions

Sponsored Content

19 Answered Questions

[SOLVED] #pragma mark in Swift?

  • 2014-06-03 14:05:56
  • Arbitur
  • 206289 View
  • 883 Score
  • 19 Answer
  • Tags:   swift

34 Answered Questions

[SOLVED] How do I create a basic UIButton programmatically?

32 Answered Questions

[SOLVED] Split a String into an array in Swift?

16 Answered Questions

[SOLVED] How to call Objective-C code from Swift

  • 2014-06-02 20:05:42
  • David Mulder
  • 264358 View
  • 905 Score
  • 16 Answer
  • Tags:   objective-c swift

16 Answered Questions

[SOLVED] Set UIButton title UILabel font size programmatically

10 Answered Questions

[SOLVED] Changing text of UIButton programmatically swift

91 Answered Questions

9 Answered Questions

[SOLVED] Swift Beta performance: sorting arrays

5 Answered Questions

[SOLVED] UIButton remove all target-actions

  • 2010-07-27 04:50:14
  • SK9
  • 71279 View
  • 325 Score
  • 5 Answer
  • Tags:   ios uibutton

3 Answered Questions

Swift 2 iOS 9 animation disappears after button text changed

  • 2015-08-10 09:11:34
  • nepete
  • 1138 View
  • 1 Score
  • 3 Answer
  • Tags:   ios swift2

Sponsored Content