UIViewController+SF.swift

//
//  UIViewController+SF.swift
//  BowenEdu
//
//  Created by CHENWANFEI on 2018/8/21.
//  Copyright © 2018 swordfish. All rights reserved.
//

import UIKit
extension UIViewController{
  
    
    @objc private func onInputTextFieldEditing(tf:UITextField){
        
        let alertController = self.presentedViewController as! UIAlertController
        let saveAction = alertController.actions.first!
        if let text = tf.text?.trimed,text.count > 0{
            saveAction.isEnabled = true
        }else{
            saveAction.isEnabled = false
        }
    }
    
    func popupInputDialog(initString:String?,title:String?,message:String?,placeholder:String?, keyboardType:UIKeyboardType = UIKeyboardType.default,  callback:@escaping (String) -> Void){
        let alertController = UIAlertController(title: title, message: message, preferredStyle: .alert)
        
        let saveAction = UIAlertAction(title: "确定", style: .default, handler: { alert -> Void in
            let firstTextField = alertController.textFields![0] as UITextField
            callback(firstTextField.text!)
            
        })
        
        alertController.addTextField { [weak self](textField : UITextField!) -> Void in
            
            guard let `self` = self else{
                return
            }
            
            textField.placeholder = placeholder
            textField.text = initString
            textField.keyboardType = keyboardType
            
        
            textField.addTarget(self, action: #selector(self.onInputTextFieldEditing(tf:)), for: .editingChanged)
          
            
            if let text = initString?.trimmingCharacters(in: CharacterSet.whitespacesAndNewlines),text.count > 0{
                saveAction.isEnabled = true
            }else{
                saveAction.isEnabled = false
            }
            
        }
       
        let cancelAction = UIAlertAction(title: "取消", style: .cancel, handler: nil)
        
        alertController.addAction(saveAction)
        alertController.addAction(cancelAction)
        
        self.present(alertController, animated: true, completion: nil)
    }
}