【Xcode/Swift】PKHUDというライブラリを使ってみよう

import UIKit
import PKHUD

class ViewController: UIViewController {
    
    @IBOutlet private weak var successButton: UIButton!
    @IBOutlet private weak var errorButton: UIButton!
    @IBOutlet private weak var loadingButton: UIButton!
    @IBOutlet private weak var textButton: UIButton!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupView()
    }
    
    private func setupView() {
        successButton.layer.cornerRadius = 20.0
        errorButton.layer.cornerRadius = 20.0
        loadingButton.layer.cornerRadius = 20.0
        textButton.layer.cornerRadius = 20.0
    }
    
    @IBAction func successAction(_ sender: Any) {
        HUD.flash(.success, delay: 1.0)
    }
    
    @IBAction func errorAction(_ sender: Any) {
        HUD.flash(.error, delay: 1.0)
    }
    
    
    @IBAction func loadingAction(_ sender: Any) {
        HUD.flash(.progress, delay: 1.0)
        
    }
    
    @IBAction func textAction(_ sender: Any) {
        HUD.flash(.label("テキストメッセージを表示するよ"), delay: 1.0)
    }
    
}