Create UIButton programmatically swift

UIButton.swift

//
//  MainView.swift
//  SeyoungARBasic
//
//  Created by YOUNG on 16/08/2017.
//  Copyright © 2017 YOUNG. All rights reserved.
//

import UIKit

/// View for MainViewController
class MainView: UIView {
    
    
    var resetButton: UIButton!
    
    let buttonHeight:CGFloat = 100
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        
    }
    
    convenience init(frame: CGRect, targetViewController target: UIViewController, resetSelector: Selector) {
        self.init(frame: frame)
        
        /// Create resetButton
        let resetButtonRect = CGRect(
        x: Constants.screenWidth/2,
        y: Constants.screenHeight - buttonHeight,
        width: Constants.screenWidth/2,
        height: buttonHeight
        )
        resetButton = UIButton(frame: resetButtonRect)
        
        createButton(
            button: resetButton,
            backgroundColor: UIColor(red: 0.8, green: 0.8, blue: 0.8, alpha: 0.5),
            titleColor: .blue,
            title: "Reset",
            target: target,
            selector: resetSelector
        )
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("This class does not support NSCoding")
    }
    
    func createButton(
        button: UIButton,
        backgroundColor: UIColor,
        titleColor: UIColor,
        title: String,
        state: UIControlState = .normal,
        target: UIViewController,
        selector: Selector
        ) {
        
        
        button.setTitle(title, for: state)
        
        button.backgroundColor = backgroundColor
        button.setTitleColor(titleColor, for: state)
        button.setTitleColor(.black, for: .highlighted)
        button.titleLabel?.font = button.titleLabel?.font.withSize(30)
        
        button.addTarget(target, action: selector, for: .touchUpInside)
        
        self.addSubview(button)
    }
    
}