redraw a custom UIVIEW when device orientation changed SWIFT 5 - swift

Question

I wrote the code down for new UIVIEW but after device rotation the draw of UIVIEW do not get cleaned up for new situation! And stay visible for user! look at picture. how we can fix the problem?
import UIKit
class ViewController: UIViewController
{
override func viewDidLoad()
{
super.viewDidLoad()
}
override func viewDidLayoutSubviews()
{
var drawView = UIView()
let drawViewOffsetFromTop = max( 25 , Int( view.safeAreaInsets.top ) )
let drawViewOffsetFromBottom = max( 25 , Int( view.safeAreaInsets.bottom ) )
let drawViewWidth = Int( view.frame.size.width ) - 2*25
let drawViewHeight = Int( view.frame.size.height) - drawViewOffsetFromTop - drawViewOffsetFromBottom
drawView = UIView(frame: CGRect(x: 25 , y: drawViewOffsetFromTop, width: drawViewWidth , height: drawViewHeight ))
drawView.backgroundColor = UIColor.gray
drawView.layer.cornerRadius = 15
view.addSubview(drawView)
}
}

Answer 1

You can use Autolayout to make things simple.
Remove override viewDidLayoutSubviews completely.
Use the following in viewDidLoad
override func viewDidLoad()
{
super.viewDidLoad()
var drawView = UIView()
//Setup Constraints for `drawView`
drawView.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
drawView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 25),
drawView.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -25),
drawView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 15),
drawView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: -15)
])
}
Edit: Solution without Autolayout
The issue is that your drawView is added multiple times in the view hierarchy! You can just add it once and only change the frame.
class ViewController: UIViewController {
var drawView = UIView()
override func viewDidLoad()
{
super.viewDidLoad()
view.addSubview(drawView)
drawView.backgroundColor = UIColor.gray
drawView.layer.cornerRadius = 15
}
override func viewDidLayoutSubviews()
{
let drawViewOffsetFromTop = max( 25 , Int( view.safeAreaInsets.top ) )
let drawViewOffsetFromBottom = max( 25 , Int( view.safeAreaInsets.bottom ) )
let drawViewWidth = Int( view.frame.size.width ) - 2*25
let drawViewHeight = Int( view.frame.size.height) - drawViewOffsetFromTop - drawViewOffsetFromBottom
drawView.frame = CGRect(x: 25 , y: drawViewOffsetFromTop, width: drawViewWidth , height: drawViewHeight )
}
}

Answer 2

First of all, you should not put creating UIView code in viewDidLayoutSubviews, create and add it in viewDidLoad instead. You can put view frame update code in viewDidLayoutSubviews.
The problem is you are adding drawView multiple times without removing existing ones. In addition you are initializing drawView multiple times in different lines unnecessarily.
To fix the problem, create drawView in your controller, add it to superview in viewDidLoad and edit your viewDidLayoutSubviews just like below:
class ViewController: UIViewController {
private var drawView : UIView = UIView()
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(drawView)
}
override func viewDidLayoutSubviews() {
let drawViewOffsetFromTop = max(25 , Int(view.safeAreaInsets.top))
let drawViewOffsetFromBottom = max(25 , Int(view.safeAreaInsets.bottom))
let drawViewWidth = Int(view.frame.size.width ) - 2*25
let drawViewHeight = Int(view.frame.size.height) - drawViewOffsetFromTop - drawViewOffsetFromBottom
drawView.frame = CGRect(x: 25, y: drawViewOffsetFromTop, width: drawViewWidth, height: drawViewHeight)
drawView.backgroundColor = UIColor.gray
drawView.layer.cornerRadius = 15
}
}

Answer 3

//▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
var drawView = UIView()
//▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
//█ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █
override func viewDidLoad()
{
super.viewDidLoad()
view.backgroundColor = UIColor.gray
}
//█ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █
//█ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █
override func viewDidLayoutSubviews()
{
//▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
let backView = UIView(frame: CGRect(x: 0 , y: 0, width: view.frame.size.width , height: view.frame.size.height ))
backView.backgroundColor = UIColor.gray
view.addSubview(backView)
//▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
//▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
let drawViewOffsetFromTop = max( 25 , Int( view.safeAreaInsets.top ) )
let drawViewOffsetFromBottom = max( 25 , Int( view.safeAreaInsets.bottom ) )
let drawViewOffsetFromRight = max( 25 , Int( view.safeAreaInsets.right ) )
let drawViewOffsetFromLeft = max( 25 , Int( view.safeAreaInsets.left ) )
//▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
//▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
let drawViewWidth = Int( view.frame.size.width ) - drawViewOffsetFromRight - drawViewOffsetFromLeft
let drawViewHeight = Int( view.frame.size.height) - drawViewOffsetFromTop - drawViewOffsetFromBottom
//▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
//▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
drawView = UIView(frame: CGRect(x: drawViewOffsetFromRight , y: drawViewOffsetFromTop, width: drawViewWidth , height: drawViewHeight ))
//▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
//▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
drawView.backgroundColor = UIColor.systemTeal
drawView.layer.cornerRadius = 12
drawView.layer.borderWidth = 5
drawView.layer.borderColor = UIColor.black.cgColor
view.addSubview(drawView)
//▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
}
//█ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █ █