使用自定義UIToolbar XIB iOS更改UIViewController背景色

在自定義工具欄中添加協議

protocol BackgroundColorControlDelegate: AnyObject {
    func changeBackgroundColor(sender:Any, color: UIColor)
}

import UIKit

class ColorToolbar: UIToolbar {

    @IBOutlet weak var purpleButton: UIBarButtonItem!
    @IBOutlet weak var blueButton: UIBarButtonItem!
    @IBOutlet weak var greenButton: UIBarButtonItem!
    @IBOutlet weak var yellowButton: UIBarButtonItem!
    @IBOutlet weak var redButton: UIBarButtonItem!

   var makeNotesVC = MakeNotesVC()
   var selectedColor : UIColor = UIColor.clear
   weak var delegate: BackgroundColorControlDelegate?


    override func awakeFromNib() {
        super.awakeFromNib()
        setupButtonColor()
    }

    @IBAction func colorButtonPressed(_ sender: UIBarButtonItem) {
        guard let color = sender.tintColor else {return}
        selectedColor = color
        print(selectedColor)
        delegate?.changeBackgroundColor(sender: self, color: color)
    }
    @objc func changeBgColor(){
        makeNotesVC.view.backgroundColor = selectedColor
    }
    private func setupButtonColor(){
        purpleButton.tintColor = Constants.TintColorButton.purple
        blueButton.tintColor = Constants.TintColorButton.blue
        greenButton.tintColor = Constants.TintColorButton.green
        yellowButton.tintColor = Constants.TintColorButton.yellow
        redButton.tintColor = Constants.TintColorButton.red
    }
}

從MakeNotesVC調用委托

import UIKit

class MakeNotesVC: UIViewController {

let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
@IBOutlet weak var titleTextfield: UITextField!
@IBOutlet weak var notesText: UITextView!

override func viewDidLoad() {
    super.viewDidLoad()
    addColorbutton()
}

@IBAction func saveButtonPressed(_ sender: UIBarButtonItem) {
    let newNote = Note(context: context)
    newNote.title = titleTextfield.text
    newNote.text = notesText.text
    self.navigationController?.popToRootViewController(animated: true)
}

func addColorbutton(){
    // TODO : Add Color Options Toolbar

    //Register custom toolbar
    let toolbar = UINib(nibName: "Toolbar", bundle: nil).instantiate(withOwner: nil, options: nil)[0] as! ColorToolbar
    toolbar.sizeToFit()
    toolbar.delegate = self
    //Add toolbar to keyboard
    titleTextfield.inputAccessoryView = toolbar
    notesText.inputAccessoryView = toolbar
}

}

extension MakeNotesVC: BackgroundColorControlDelegate  {
    func changeBackgroundColor(sender:Any, color: UIColor) {
        view.backgroundColor = color
    }
}