Calling a function (containing variable) in another class - ios

Question

I have a relatively simple question. I created a function - covers the contents to retrieve data from the API. I need to call a function in several different classes (don't want to duplicate). I am calling that function, but nothing is getting displayed. If this function is a part of class where I want to call it, it works correctly. Where is the problem, please let me know. (I think in UIView...)? Thank you.
My function:
func loadScreen() {
var loadView:UIView!
loadView = UIView(frame: self.view.frame)
loadView!.backgroundColor = UIColor.black
loadView!.alpha = 1.0
let actView = UIActivityIndicatorView(activityIndicatorStyle: UIActivityIndicatorViewStyle.gray)
actView.frame = CGRect(x: 0, y: 0, width: 20, height: 20)
actView.center = CGPoint(x: self.view.bounds.size.width / 2 , y: self.view.bounds.size.height / 2 )
actView.startAnimating()
loadView?.addSubview(actView)
self.view.addSubview(loadView!)
}
I call a function in another class in viewDidLoad (), but as I said, nothing is displayed.

Answer 1

First create a singleton class like this
Singleton class
import UIKit
import Foundation
class Singleton: NSObject
{
static let sharedInstance = Singleton()
override init()
{
super.init()
}
func placeBlockerView(target : UIViewController)
{
var loadView:UIView!
loadView = UIView(frame: target.view.frame)
loadView!.backgroundColor = UIColor.black
loadView!.alpha = 1.0
let actView = UIActivityIndicatorView(activityIndicatorStyle: UIActivityIndicatorViewStyle.gray)
actView.frame = CGRect(x: 0, y: 0, width: 20, height: 20)
actView.center = CGPoint(x: target.view.bounds.size.width / 2 , y: target.view.bounds.size.height / 2 )
actView.startAnimating()
loadView?.addSubview(actView)
target.view.addSubview(loadView!)
}
}
After that use it from where ever you want as required
like this
Singleton.sharedInstance.placeBlockerView(target: self)
This above line will add that UIView you have created to your view controller's view.
Let me know if it don't work.

Answer 2

Instead of adding it in the above, it is always advised to return the UIView from that method and in your subclass of UIViewController do the following.
func viewDidLoad() {
let loadView = loadScreen()
self.view.addSubView()
}