App. Chapter 19 App. App (ViewController) App. Single View Application Single View Application View. (View Controller)

Transcription

1 Chapter 19 App App (ViewController) App 19.1 App App Single View Application Single View Application View Controller View Controller Label Button Button (View Controller) 2 View Controller Utility Area View Controller Storyboard

2 Button control 2 View Controller Show View Controller Label

3 2 1

4 19.2 Segue (1) UIViewController Storyboard View Controller (2) Storyboard View Controller View Controller View Controller Button View Controller control View Controller Show Class View Controller Project Navigator MultipleViewController New File

5 New File Swift File SecondViewController Project Navigator SecondViewController.swift ViewController.swift SecondViewController.swift ( SecondViewController) 1 import UIKit 2 3 class SecondViewController: UIViewController { 4 5 override func viewdidload() { 6 super.viewdidload() 7 } 8 9 override func didreceivememorywarning() { 10 super.didreceivememorywarning() 11 } 12 } Storyboard 2 View Controller Utility Area Show the Identity inspector Class SecondViewController

6 Storyboard View Controller Segue Identifier tosecondvc

7 Storyboard 1 View Controller Go to the second view controller ViewController.swift func gotosecond(_ sender: UIButton) { 2 performsegue(withidentifier: "tosecondvc", sender: self) 3 } performsegue 1 withidentifier Storyboard Segue Identifier Storyboard 2 View Controller Finish SecondViewController.swift func finish(_ sender: UIButton) { 2 dismiss(animated: true, completion: nil) 3 } dismiss 2 View Controller 19.3 Storyboard Button View Controller View Controller Identify inspector Storyboard ID secondvc ViewController.swift func gotosecondvc(_ sender: UIButton) { 2 3 let storyboard = UIStoryboard(name: "Main", bundle: nil) 4 let secondvc = storyboard.instantiateviewcontroller( 5 withidentifier: "secondvc") 6 present(secondvc, animated: true, completion: nil)

8 7 } 3 Storyboard Main.storyboard name Main 4 Storyboard ID Storyboard View Controller 6 present 2 View Controller 19.4 View Controller (View Controller) 1 2 Storyboard Segue Identifier toresultvc ViewController ResultViewController ViewController.swift 1 class ViewController: UIViewController { 2 weak var tf_num1: UITextField! 4 weak var tf_num2: UITextField! 6 7 var num1: Int? 8 var num2: Int? 9 func calculateclicked(_ sender: UIButton) { 11 num1 = nil 12 if tf_num1.text!= nil { 13 num1 = Int(tf_num1.text!) 14 } 15 num2 = nil 16 if tf_num2.text!= nil { 17 num2 = Int(tf_num2.text!)

9 18 } 19 if num1 == nil num2 == nil { 20 return 21 } 22 performsegue(withidentifier: "toresultvc", sender: self) 23 } override func prepare(for segue: UIStoryboardSegue, sender:any?) { 26 let resultvc = segue.destination as! ResultViewController 27 resultvc.num1 = num1 28 resultvc.num2 = num2 29 } override func viewdidload() { 32 super.viewdidload() 33 } override func didreceivememorywarning() { 36 super.didreceivememorywarning() 37 } 38 } 25 ~ 29 prepare performsegue prepare prepare segue ViewController 26 segue.destination View Controller ResultViewController

10 19.5 View Controller View Controller ViewController Label ResultViewController Label ResultViewController previousvc ( ViewController?) ViewController.swift prepare 1 override func prepare(for segue: UIStoryboardSegue, sender: Any?) { 2 let resultvc = segue.destination as! ResultViewController 3 resultvc.num1 = num1 4 resultvc.num2 = num2 5 resultvc.previousvc = self 6 } 5 previousvc ViewController ResultViewController.swift viewdidload 1 override func viewdidload() { 2 super.viewdidload() 3 4 if num1 == nil num2 == nil { 5 return 6 } 7 result = num1! + num2! 8 resultlabel.text = "\(num1!)+\(num2!)=\(result!)" 9 10 if previousvc!= nil { 11 previousvc!.resultlabel.text = resultlabel.text 12 } 13 } ViewController.swift previousvc 11 previousvc

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