使用閉包和代理和Segue進行反向傳值
阿新 • • 發佈:2017-05-05
closure create 賦值 返回 protocol alt 類型 del uiview
import UIKit class FirstViewController: UIViewController, SecondViewControllerDelegate { @IBOutlet weak var showTextLabel: UILabel! @IBOutlet weak var showDelegateTextLabel: UILabel! override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view. } //點擊按鈕跳轉到SecondViewController @IBAction func tapGoSecondViewController(sender: UIButton) { //從storyboard上加載SecondViewController let secondVC = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle()).instantiateViewControllerWithIdentifier("secondViewController") as! SecondViewController //實現回調,獲取回調回來的值 (閉包)secondVC.backClosure = { (backStr: String) -> Void in self.showTextLabel.text = backStr } secondVC.delegate = self //跳轉到SecondViewController self.navigationController?.pushViewController(secondVC, animated: true) } //MARK: - SecondViewControllerDelegate(代理) func fetchBackString(str: String) { self.showDelegateTextLabel.text = str } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } }
import UIKit
//定義閉包類型(特定的函數類型函數類型)
typealias InputClosureType = (String) -> Void
protocol SecondViewControllerDelegate:
NSObjectProtocol
{
func fetchBackString(str: String)
}
class
SecondViewController: UIViewController {
@IBOutlet
weak var inputTextField: UITextField!
//接收上個頁面傳過來的閉包塊
var backClosure: InputClosureType?
weak var delegate: SecondViewControllerDelegate?
override func viewDidLoad() {
super
.viewDidLoad()
// Do any additional setup after loading the view.
}
@IBAction
func tapBackButton(sender: UIButton) {
if
self
.backClosure !=
nil
{
if
let tempString =
self
.inputTextField.text {
self
.backClosure!(tempString)
}
}
self
.navigationController?.popViewControllerAnimated(
true
)
}
@IBAction
func delegateBackMethod(sender: UIButton) {
if
self
.delegate !=
nil
{
if
let tempString =
self
.inputTextField.text {
delegate!.fetchBackString(
"代理返回數據:\(tempString)"
)
}
}
self
.navigationController?.popViewControllerAnimated(
true
)
}
override func didReceiveMemoryWarning() {
super
.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
利用Segue進行轉場傳值
正向跳轉
segue正向轉場是prepareForSegue
在源VC中->NavigationViewController在Segue的屬性中選擇show(Xcode7.2沒有show detail),會有返場btn,將VC push進下一個場景。源VC中用prepareForSegue進行設置,在方法中確定目的VC,然後對目的VC中的屬性進行賦值或傳遞方法。
反向轉場
模態展現(modal)的視圖系統不提供返回按鈕。我們需要定義一個反向轉場,可以用模態視圖退場。
在目的視圖定義這個函數
@IBAction func close(segue:UIStoryboardSegue){
裏面放傳遞的數據
}
在跳轉VC中按control拖btn到exit,選擇close。
反向轉場用performSegueWithIdentifier.
btn拖到exit->出口執行目的地VC中的自定義函數
@IBAction func close(segue:UIStoryboardSegue)
{
let sourceVC = segue.sourceViewController as 源VC
(獲取sourceVC中的對象或者數據後在destVC中進行處理)
}
使用閉包和代理和Segue進行反向傳值