Make a UIButton programmatically in Swift

I am trying to build UIs programmatically with Swift.

How can I get this action working?

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();
}

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 = .red
    myFirstLabel.textAlignment = .center
    myFirstLabel.numberOfLines = 5
    myFirstLabel.frame = CGRect(x: 15, y: 54, width: 300, height: 500)
    myFirstButton.setTitle("✸", for: .normal)
    myFirstButton.setTitleColor(.blue, for: .normal)
    myFirstButton.frame = CGRect(x: 15, y: -50, width: 300, height: 500)
    myFirstButton.addTarget(self, action: #selector(pressed), for: .touchUpInside)
}

@objc func pressed() {
    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.

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")
}

Swift 4/5

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
            }

Swift 4

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

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

}

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")
    }
}

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

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..
}

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)

@objc 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

}

Swift 5.0

        let button = self.makeButton(title: "Login", titleColor: .blue, font: UIFont.init(name: "Arial", size: 18.0), background: .white, cornerRadius: 3.0, borderWidth: 2, borderColor: .black)
        view.addSubview(button)
        // Adding Constraints
        button.heightAnchor.constraint(equalToConstant: 40).isActive = true
        button.leftAnchor.constraint(equalTo: view.leftAnchor, constant: 40).isActive = true
        button.rightAnchor.constraint(equalTo: view.rightAnchor, constant: -40).isActive = true
        button.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -400).isActive = true
        button.addTarget(self, action: #selector(pressed(_ :)), for: .touchUpInside)

       // Define commmon method
        func makeButton(title: String? = nil,
                           titleColor: UIColor = .black,
                           font: UIFont? = nil,
                           background: UIColor = .clear,
                           cornerRadius: CGFloat = 0,
                           borderWidth: CGFloat = 0,
                           borderColor: UIColor = .clear) -> UIButton {
        let button = UIButton()
        button.translatesAutoresizingMaskIntoConstraints = false
        button.setTitle(title, for: .normal)
        button.backgroundColor = background
        button.setTitleColor(titleColor, for: .normal)
        button.titleLabel?.font = font
        button.layer.cornerRadius = 6.0
        button.layer.borderWidth = 2
        button.layer.borderColor = UIColor.red.cgColor
        return button
      }
        // Button Action
         @objc func pressed(_ sender: UIButton) {
                print("Pressed")
          }

[![enter image description here][1]][1] [1]: https://i.stack.imgur.com/XAHsm.png

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)")
}

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

I have given the example for create the button and set constraint in coding. This code also contains the programmatically button action.

import UIKit

class ViewController: UIViewController {
  
  
  lazy var button: UIButton! = {
    
    let button = UIButton()
    button.translatesAutoresizingMaskIntoConstraints = false
    button.backgroundColor = .darkGray
    button.setTitleColor(.white, for: .normal)
    button.addTarget(self, action: #selector(didTaped(_:)), for: .touchUpInside)
    button.tag = 1
    button.setTitle("Tap", for: .normal)
    return button
    
  }()
  
  lazy var label: UILabel! = {
    
    let label = UILabel()
    label.translatesAutoresizingMaskIntoConstraints = false
    label.textColor = .black
    label.font = .systemFont(ofSize: 17)
    label.textAlignment = .center
    return label
    
  }()
    
  override var preferredStatusBarStyle: UIStatusBarStyle{
    return .darkContent
  }
  
  override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.
    self.view.backgroundColor = .white
    self.setConstraint()
    
  }
  
  @objc func didTaped(_ sender: UIButton){
    
    self.label.text = "No of times Taped: \(sender.tag)"
    self.button.tag += 1
    
  }
  
  func setConstraint(){
    
    self.view.addSubview(self.button)
    self.view.addSubview(self.label)
    
    NSLayoutConstraint.activate([
    
      self.button.heightAnchor.constraint(equalToConstant: 60),
      self.button.widthAnchor.constraint(equalToConstant: UIScreen.main.bounds.width * 0.66),
      self.button.centerXAnchor.constraint(equalTo: self.view.centerXAnchor),
      self.button.centerYAnchor.constraint(equalTo: self.view.centerYAnchor),
      
      self.label.centerXAnchor.constraint(equalTo: self.view.centerXAnchor),
      self.label.topAnchor.constraint(equalTo: self.button.topAnchor, constant: UIScreen.main.bounds.height * 0.12),
      self.label.leadingAnchor.constraint(equalTo: self.view.leadingAnchor, constant: 10),

    ])

  }
  
}

Output:

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

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
}

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")
}

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.

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
    }
}

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
}()

In iOS 15 apple has introduced configuration(.gray(), .filled() and more) with the Button. There are lot more options with configuration.

 var grayButton: UIButton!

 func addButton() {
    grayButton = UIButton(configuration: .gray())
    grayButton.addTarget(self, action: #selector(buttonPressed(_:)), for: .touchUpInside)
    grayButton.frame = CGRect(x: 10, y: 50, width: 150, height: 50)
    grayButton.configuration?.title = "Press Me"
    grayButton.configuration?.subtitle = "Sub Title"
    grayButton.configuration?.image = UIImage(systemName: "house")
    grayButton.configuration?.imagePadding = 10
    grayButton.configuration?.imagePlacement = .leading
    view.addSubview(grayButton)
}

@objc func buttonPressed(_ sender: UIButton) {
    grayButton.configuration?.showsActivityIndicator = true
    DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
        self.grayButton.configuration?.showsActivityIndicator = false
    }
}

Also we can show and hide activity indicator inside the button with showsActivityIndicator property.

   override func viewDidLoad() {
        super.viewDidLoad()
        let menuButton = UIButton(frame: .zero)
        menuButton.addTarget(self, action: #selector(menuTapped), for: .touchUpInside)
        view.addSubView(menuButton)
    }

    @objc func menuTapped() {
        // do Stuff
    }

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.