// UILabel:
    let label = UILabel()
    label.frame = CGRectMake(35, 100, 250, 30)
    label.textColor = UIColor.blackColor()
    label.textAlignment = NSTextAlignment.Center
    label.text = "Hello World"
    self.view.addSubview(label)

    // UIButton:
    let btn: UIButton = UIButton(type: UIButtonType.Custom) as UIButton
    btn.frame = CGRectMake(130, 70, 60, 20)
    btn.setTitle("Click", forState: UIControlState.Normal)
    btn.setTitleColor(UIColor.blackColor(), forState: .Normal)
    btn.addTarget(self, action:Selector("clickAction"), forControlEvents: UIControlEvents.TouchUpInside)
    view.addSubview(btn)


    // Button Action:
    @IBAction func clickAction(sender:AnyObject)
    {
        print("Click Action")
    }

API没有改变——只有语法改变了。你可以创建一个UIButton并像这样添加它:

var button = UIButton(frame: CGRectMake(0, 0, 50, 50))
self.view.addSubview(button) // assuming you're in a view controller

 var sampleButton:UIButton?

 override func viewDidLoad() {
  super.viewDidLoad()

 }
 override func viewDidAppear(animated: Bool) {

  sampleButton = UIButton(type: .RoundedRect)
  //sampleButton.frame = CGRect(x:50, y:500, width:70, height:50)

  sampleButton!.setTitle("Sample \n UI Button", forState: .Normal)
  sampleButton!.titleLabel?.lineBreakMode = .ByWordWrapping
  sampleButton!.titleLabel?.textAlignment = .Center
  sampleButton!.setTitleColor(UIColor.whiteColor(), forState: .Normal)
  sampleButton!.layer.cornerRadius = 6
  sampleButton!.backgroundColor = UIColor.redColor().colorWithAlphaComponent(0.6)
  sampleButton?.tintColor =  UIColor.brownColor()


  //Add padding around text
  sampleButton!.titleEdgeInsets = UIEdgeInsetsMake(-10,-10,-10,-10)
  sampleButton!.contentEdgeInsets = UIEdgeInsetsMake(5,5,5,5)

  //Action set up
  sampleButton!.addTarget(self, action: "sampleButtonClicked", forControlEvents: .TouchUpInside)
  self.view.addSubview(sampleButton!)


  //Button Constraints:
  sampleButton!.translatesAutoresizingMaskIntoConstraints = false

  //To anchor above the tab bar on the bottom of the screen:
  let bottomButtonConstraint = sampleButton!.bottomAnchor.constraintEqualToAnchor(bottomLayoutGuide.topAnchor, constant: -20)

  //edge of the screen in InterfaceBuilder:
  let margins = view.layoutMarginsGuide
  let leadingButtonConstraint = sampleButton!.leadingAnchor.constraintEqualToAnchor(margins.leadingAnchor)

  bottomButtonConstraint.active = true
  leadingButtonConstraint.active = true


 }
 func sampleButtonClicked(){

  print("sample Button Clicked")

 }

这对我来说非常好，#DynamicButtonEvent #IOS #Swift #Xcode

func setupButtonMap(){
    let mapButton = UIButton(type: .system)
    mapButton.setImage(#imageLiteral(resourceName: "CreateTrip").withRenderingMode(.alwaysOriginal), for: .normal)
    mapButton.frame = CGRect(x: 0, y: 0, width: 34, height: 34)
    mapButton.contentMode = .scaleAspectFit
    mapButton.backgroundColor = UIColor.clear
    mapButton.addTarget(self, action: #selector(ViewController.btnOpenMap(_:)), for: .touchUpInside)
    navigationItem.leftBarButtonItem = UIBarButtonItem(customView: mapButton)
    }
@IBAction func btnOpenMap(_ sender: Any?) {
    print("Successful")
}

下面是一个完整的解决方案，以编程方式添加一个UIButton与targetAction。 斯威夫特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")
}

使用NSLayoutConstraint而不是frame来正确地为每个iPhone屏幕放置按钮可能更好。

Swift 3.1的更新代码:

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")
}

Swift 4.2的更新代码:

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")
}

如果func buttonAction声明为private或internal，上述方法仍然有效。

Uilabel code 

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