func viewDidLoad(){
                    saveActionButton = UIButton(frame: CGRect(x: self.view.frame.size.width - 60, y: 0, width: 50, height: 50))
                    self.saveActionButton.backgroundColor = UIColor(red: 76/255, green: 217/255, blue: 100/255, alpha: 0.7)
                    saveActionButton.addTarget(self, action: #selector(doneAction), for: .touchUpInside)
                    self.saveActionButton.setTitle("Done", for: .normal)
                    self.saveActionButton.layer.cornerRadius = self.saveActionButton.frame.size.width / 2
                    self.saveActionButton.layer.borderColor = UIColor.darkGray.cgColor
                    self.saveActionButton.layer.borderWidth = 1
                    self.saveActionButton.center.y = self.view.frame.size.height - 80
                    self.view.addSubview(saveActionButton)
        }

          func doneAction(){
          print("Write your own logic")
         }

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)

是的，在模拟器里。有时它不会识别选择器，这似乎是一个错误。即使我面对的不是你的代码，然后我只是改变了动作名称(选择器)。它的工作原理

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)

选择器函数在这里:

func buttonAction(sender:UIButton!)
{

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

你可以通过这种方式添加UIButton,UIlable和UITextfield。

UIButton代码

// var button   = UIButton.buttonWithType(UIButtonType.System) as UIButton
let button = UIButton(type: .System) // let preferred over var here
button.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代码

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)

UITextField 代码

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

希望这对你有帮助。

            let myFirstButton = UIButton()
            myFirstButton.setTitle("Software Button", forState: .Normal)
            myFirstButton.setTitleColor(UIColor.redColor(), forState: .Normal)
            myFirstButton.frame = CGRectMake(100, 300, 150, 50)
            myFirstButton.backgroundColor = UIColor.purpleColor()
            myFirstButton.layer.cornerRadius = 14
            myFirstButton.addTarget(self, action: "pressed:", forControlEvents: .TouchUpInside)
            self.view.addSubview(myFirstButton)
            myFirstButton.hidden=true
            nameText.delegate = self


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

 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")

 }