Swift:以编程方式创建Ui按钮

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
self.view.addSubview(myButton)

这是可能的。除了使用swift语法之外，您几乎可以以相同的方式完成所有操作。例如，你可以用这样的代码创建一个UIButton:

 var button: UIButton = UIButton(frame: CGRectMake(0, 0, 100, 100))

在Swift 4.2中编写下面的示例代码，用于以编程方式添加按钮。

override func viewDidLoad() {
    super.viewDidLoad()
        let myButton = UIButton(frame: CGRect(x: 100, y: 100, width: 100, height: 50))
        myButton.backgroundColor = .green
        myButton.setTitle("Hello UIButton", for: .normal)
        myButton.addTarget(self, action: #selector(myButtonAction), for: .touchUpInside)
        self.view.addSubview(myButton)
}

 @objc func myButtonAction(sender: UIButton!) {
    print("My Button tapped")
}

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

Swift 5和Swift 4一样

 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")
 }

 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")

 }