How to create a button programmatically?

Here is a complete solution to add a UIButton programmatically with the targetAction.
Swift 2.2

override func viewDidLoad() {  super.viewDidLoad()  let button = UIButton(frame: CGRect(x: 100, y: 100, width: 100, height: 50))  button.backgroundColor = .greenColor()  button.setTitle("Test Button", forState: .Normal)  button.addTarget(self, action: #selector(buttonAction), forControlEvents: .TouchUpInside)  self.view.addSubview(button)}func buttonAction(sender: UIButton!) {  print("Button tapped")}

It is probably better to use NSLayoutConstraint rather than frame to correctly place the button for each iPhone screen.

Updated code to Swift 3.1:

override func viewDidLoad() {  super.viewDidLoad()  let button = UIButton(frame: CGRect(x: 100, y: 100, width: 100, height: 50))  button.backgroundColor = .green  button.setTitle("Test Button", for: .normal)  button.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)  self.view.addSubview(button)}func buttonAction(sender: UIButton!) {  print("Button tapped")}

Updated code to Swift 4.2:

override func viewDidLoad() {  super.viewDidLoad()  let button = UIButton(frame: CGRect(x: 100, y: 100, width: 100, height: 50))  button.backgroundColor = .green  button.setTitle("Test Button", for: .normal)  button.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)  self.view.addSubview(button)}@objc func buttonAction(sender: UIButton!) {  print("Button tapped")}

The above still works if func buttonAction is declared private or internal.

You can add UIButton,UIlable and UITextfield programmatically in this way.

UIButton code

// var button   = UIButton.buttonWithType(UIButtonType.System) as UIButtonlet button = UIButton(type: .System) // let preferred over var herebutton.frame = CGRectMake(100, 100, 100, 50)button.backgroundColor = UIColor.greenColor()button.setTitle("Button", forState: UIControlState.Normal)button.addTarget(self, action: "Action:", forControlEvents: UIControlEvents.TouchUpInside)self.view.addSubview(button)

UILabel Code

var label: UILabel = UILabel()label.frame = CGRectMake(50, 50, 200, 21)label.backgroundColor = UIColor.blackColor()label.textColor = UIColor.whiteColor()label.textAlignment = NSTextAlignment.Centerlabel.text = "test label"self.view.addSubview(label)

UITextField code

var txtField: UITextField = UITextField()txtField.frame = CGRectMake(50, 70, 200, 30)txtField.backgroundColor = UIColor.grayColor()self.view.addSubview(txtField)

Hope this is helpful for you.

For Swift 3

let button = UIButton()button.frame = CGRect(x: self.view.frame.size.width - 60, y: 60, width: 50, height: 50)button.backgroundColor = UIColor.redbutton.setTitle("your Button Name", for: .normal)button.addTarget(self, action: #selector(buttonAction), for: .touchUpInside)self.view.addSubview(button)func buttonAction(sender: UIButton!) {    print("Button tapped")}

For Swift 4+

 let button = UIButton() button.frame = CGRect(x: self.view.frame.size.width - 60, y: 60, width: 50, height: 50) button.backgroundColor = UIColor.red button.setTitle("Name your Button ", for: .normal) button.addTarget(self, action: #selector(buttonAction), for: .touchUpInside) self.view.addSubview(button) @objc func buttonAction(sender: UIButton!) {    print("Button tapped") }