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();
    }

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))

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")
 }

步骤1:创建一个新项目

步骤2:在ViewController.swift中

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // CODE
        let btn = UIButton(type: UIButtonType.System) as UIButton        
        btn.backgroundColor = UIColor.blueColor()
        btn.setTitle("CALL TPT AGENT", forState: UIControlState.Normal)
        btn.frame = CGRectMake(100, 100, 200, 100)
        btn.addTarget(self, action: "clickMe:", forControlEvents: UIControlEvents.TouchUpInside)
        self.view.addSubview(btn)

    }

    func clickMe(sender:UIButton!) {
      print("CALL")
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

斯威夫特3

let btn = UIButton(type: .custom) as UIButton
btn.backgroundColor = .blue
btn.setTitle("Button", for: .normal)
btn.frame = CGRect(x: 100, y: 100, width: 200, height: 100)
btn.addTarget(self, action: #selector(clickMe), for: .touchUpInside)
self.view.addSubview(btn)

func clickMe(sender:UIButton!) {
  print("Button Clicked")
}

输出