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The rabbit by Dennis Heidrich on 500px.com

接上一篇利用協議擴展封裝ProgressHUD，這幾天琢磨著逐步把BaseViewController中的方法挪出來，進一步給BaseViewController減肥。

iOS 8開始蘋果推薦使用UIAlertController替代原有的UIAlertView，關于UIAlertView的使用，推薦參看UIAlertView-Blocks。今天要介紹的是我封裝的一個UIAlertController的方法，利用Swift的協議擴展和默認參數，簡化了UIAlertController的使用。

import Foundation

// MARK: - UIAlertViewable

protocol UIAlertViewable {
    func showAlertAction(title title: String?, message: String?, okTitle: String, cancelTitle: String?, okAction: ((Void) -> Void)?, cancelAction: ((Void) -> Void)?)
}

extension UIAlertViewable where Self: UIViewController {
    
    func showAlertAction(title title: String? = nil, message: String? = nil,
                               okTitle: String = NSLocalizedString("ok", comment: "確定"), cancelTitle: String? = nil,
                               okAction: ((Void) -> Void)? = nil, cancelAction: ((Void) -> Void)? = nil) {
        
        let alertController = UIAlertController(title: title, message: message, preferredStyle: .Alert)
        
        let okAction = UIAlertAction(title: okTitle, style: .Default) { _ in
            if let handler = okAction {
                handler()
            }
        }
        alertController.addAction(okAction)
        
        if let title = cancelTitle {
            let cancelAction = UIAlertAction(title: title, style: .Cancel) { _ in
                if let handler = cancelAction {
                    handler()
                }
            }
            alertController.addAction(cancelAction)
        }
        
        presentViewController(alertController, animated: true, completion: nil)
    }
    
}

如何使用？

class LoginViewController: UIViewController, UIAlertViewable {
    ...
}

//只顯示確定
showAlertAction(title: title, message: message, okTitle: "確定")

//顯示確定和取消
showAlertAction(title: title, message: message, 
                okTitle: "確定", cancelTitle: "取消")
                
//顯示確定和取消，并帶有響應方法
showAlertAction(title: title, message: message, 
                okTitle: "確定", cancelTitle: "取消",        
                okAction: { [unowned self] _ in
                    //to do
                },
                cancelAction: { [unowned self] _ in
                    //to do
                })

我是咕咕雞，一個還在不停學習的全棧工程師。
熱愛生活，喜歡跑步，家庭是我不斷向前進步的動力。