import UIKit
import Foundation
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let rect = CGRect(x:30,y:50,width:200,height:200)
let view = UIView(frame:rect)
view.backgroundColor = UIColor.brown
self.view.addSubview(view)
let btAdd = UIButton(frame:CGRect(x:30,y:350,width:80,height:30))
btAdd.backgroundColor = UIColor.gray
btAdd.setTitle("Add", for:UIControlState())
btAdd.addTarget(self, action:#selector(ViewController.addView(_:)),for:UIControlEvents.touchUpInside)
self.view.addSubview(btAdd)
let btBack = UIButton(frame:CGRect(x:120,y:350,width:80,height:30))
btBack.backgroundColor = UIColor.gray
btBack.setTitle("Switch", for: UIControlState())
btBack.addTarget(self, action:#selector(ViewController.bringViewBack(_:)),for:UIControlEvents.touchUpInside)
self.view.addSubview(btBack)
let btRemove = UIButton(frame:CGRect(x:210,y:350,width:80,height:30))
btRemove.backgroundColor = UIColor.gray
btRemove.setTitle("Remove", for: UIControlState())
btRemove.addTarget(self, action:#selector(ViewController.removeView(_:)),for:UIControlEvents.touchUpInside)
self.view.addSubview(btRemove)}
@objc func addView(_ sender:UIButton!)
{let rect = CGRect(x:60,y:90,width:200,height:200)
let view = UIView(frame:rect)
view.backgroundColor = UIColor.purple
view.tag = 1;
self.view.addSubview(view)
}
@objc func bringViewBack(_ sender:UIButton!)
{let view = self.view.viewWithTag(1)
self.view.sendSubview(toBack:view!)
}
@objc func removeView(_ sender:UIButton!)
{let view = self.view.viewWithTag(1)
view?.removeFromSuperview()}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}