UIViewController + extension

UIViewController + extension.md

UIViewController + extension

import UIKit

extension UIViewController {
    
    /// [UIViewController+] 画面のスクリーンショットを取る
    func e_screenshotFromWindow(scale: CGFloat = 0.0) -> UIImage? {
        guard let window = UIApplication.sharedApplication().windows.first else {
            return nil
        }
        UIGraphicsBeginImageContextWithOptions(window.frame.size, false, scale)
        window.drawViewHierarchyInRect(window.bounds, afterScreenUpdates: true)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

★ UIAlertControllerを拡張

extension UIViewController {
    
    // １つボタンのアラートを生成
    func oneButtonAlert(title  : String = nil,
                        message: String = nil,
                        button : String = nil,
                        handler: @escaping () -> ()) {
        
        let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
        
        let action1 = UIAlertAction(title: button, style: .default, handler: { action in
            handler()
        })
        
        alert.addAction(action1)
        present(alert, animated: true, completion: nil)
    }
    
    // ２つボタンのアラートを生成
    func twoButtonAlert(title   : String = nil,
                        message : String = nil,
                        button1 : String = nil,
                        button2 : String = nil,
                        handler1: @escaping () -> (),
                        handler2: @escaping () -> ()) {
        
        let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
        
        let action1 = UIAlertAction(title: button1, style: .default, handler: { action in
            handler1()
        })
        
        let action2 = UIAlertAction(title: button2, style: .default, handler: { action in
            handler2()
        })
        
        alert.addAction(action1)
        alert.addAction(action2)
        present(alert, animated: true, completion: nil)
    }
}

// Usage

VC.oneButtonAlert(title:   "Title",
                  message: "Message",
                  button:  "OK") {
                        
                  // Button Tap Event
}

• 全てのModal画面を閉じる

import UIKit

class TopViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

    }
    
    @IBAction func dismiss(_ sender: UIButton) {
        
        // 全てのモーダルを閉じる
        dismissAll(animated: true) {
            
        }
    }
}


extension UIViewController {
    func dismissAll(animated: Bool, completion: (() -> Void)?) {
        
        var presentingViewController = UIApplication.shared.topViewController?.presentingViewController
        guard let _ = presentingViewController?.presentingViewController else {
            completion?()
            return
        }
        
        while let presenting = presentingViewController?.presentingViewController {
            presentingViewController = presenting
        }
        presentingViewController?.dismiss(animated: animated, completion: {
            completion?()
        })
    }
}

extension UIApplication {
    var topViewController: UIViewController? {
        guard var topViewController = UIApplication.shared.keyWindow?.rootViewController else { return nil }
        while let presentedViewController = topViewController.presentedViewController {
            topViewController = presentedViewController
        }
        return topViewController
    }
}