How to get a UIButton to perform action in a Swift Playground

大兔子大兔子 提交于 2019-12-06 09:51:02

Minor change of your code and it worked for me.

For anyone who meet the same problem, suggestion:

  1. Define a Responser class.
  2. write the action you want to link to button inside this class
  3. define an instance of Responser
  4. addTarget to the instance and link the action

Code Example

import PlaygroundSupport
import UIKit

//
let view = UIView()
view.backgroundColor = #colorLiteral(red: 0.909803926944733, green: 0.47843137383461, blue: 0.643137276172638, alpha: 1.0)
view.frame = CGRect(x: 0, y: 0, width: 400, height: 300)


let lbl = UILabel(frame: CGRect(x: 50, y: 0, width: 200, height: 50))
lbl.text = "Hello, World!"
view.addSubview(lbl)

let txt = UITextField(frame: CGRect(x: 150, y: 200, width: 200, height: 50))
txt.placeholder = "Enter text here"
//txt.font = UIFont.systemFont(ofSize: 15)
txt.backgroundColor = #colorLiteral(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
txt.borderStyle = UITextBorderStyle.roundedRect

view.addSubview(txt)

let button = UIButton(frame: CGRect(x: 50, y: 100, width: 100, height: 50))
button.backgroundColor = #colorLiteral(red: 0.721568644046783, green: 0.886274516582489, blue: 0.592156887054443, alpha: 1.0)
//button.setTitleColor(#colorLiteral(red: 0.0, green: 0.0, blue: 0.0, alpha: 1.0), for: UIControlState.selected)
button.setTitle("button", for: UIControlState.selected)
button.layer.cornerRadius = 10
view.addSubview(button)

class Responser: NSObject
{

    //Method to be called
    func printname()
    {
        print ("clicked")
        lbl.text = "aha"
    }
}

let responder = Responser()
button.addTarget(responder, action: #selector(Responser.printname), for:.touchUpInside)

PlaygroundPage.current.liveView = view
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