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Swift使用delegate和closure進行傳值：類似oc的代理和block

firstViewController.swift文件

import UIKit

class firstViewController:UIViewController,passValueDelegate {

var passValueLabel:UILabel!
override func viewDidLoad() {
    super.viewDidLoad()

    self.view.backgroundColor =UIColor.whiteColor()
    let pushBtn =UIButton(type: .Custom)
    pushBtn.frame =CGRectMake(100,150, kMainScreenWidth -200, 40)
    pushBtn.setTitle("secondCon", forState: .Normal)
    self.view.addSubview(pushBtn)
    pushBtn.addTarget(self, action:Selector("pushTosecondViewController"), forControlEvents: .TouchUpInside)
    pushBtn.setTitleColor(UIColor.redColor(), forState: .Normal)
    passValueLabel =UILabel.init(frame:CGRectMake(20,100, kMainScreenWidth -40, 30))
    passValueLabel.backgroundColor =UIColor.grayColor()
    self.view.addSubview(passValueLabel)
    
    // Do any additional setup after loading the view.
}

func pushTosecondViewController() {
    let secondCon =secondViewController()
    
    //利用閉包傳值：跟oc的block很像
    secondCon.myClosure = {
        [unowned self](newValue:AnyObject) ->Void
        in
        self.passValueLabel.text = newValueas? String
    }
    secondCon.delegate =self
    
    self.navigationController?.pushViewController(secondCon, animated:true)
}
override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

//MARK: - passValueDelegate代理回調
func passValue(newValue:AnyObject) {
print("接收代理回調的值:(newValue)")
passValueLabel.text = newValueas? String
}
/*
// MARK: - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    // Get the new view controller using segue.destinationViewController.
    // Pass the selected object to the new view controller.
}
*/

}

secondViewController.swift文件
import UIKit

//利用代理傳值
protocol passValueDelegate:NSObjectProtocol {

func passValue(newValue:AnyObject)

}

//閉包回調傳值
typealias sendValueClosure = (newValue:AnyObject) ->Void

class secondViewController: UIViewController {

var myClosure:sendValueClosure?
weakvar delegate:passValueDelegate?
var textField:UITextField!
override func viewDidLoad() {
    super.viewDidLoad()

    self.view.backgroundColor =UIColor.whiteColor()

    textField = UITextField.init(frame: CGRectMake(20, 100, kMainScreenWidth - 40, 30))
    textField.backgroundColor =UIColor.yellowColor()

    textField.placeholder ="輸入newValue"
    self.view.addSubview(textField)
    
    let delegateBtn = UIButton(type: .Custom)
    delegateBtn.frame = CGRectMake(20, 150, kMainScreenWidth/2.0 -40, 40)
    delegateBtn.setTitleColor(UIColor.redColor(), forState: .Normal)
    delegateBtn.setTitle("delegate傳值", forState: .Normal)
    self.view.addSubview(delegateBtn)
    delegateBtn.addTarget(self, action:Selector("delegatePassValueBtnPressed"), forControlEvents: .TouchUpInside)
    
    let closureBtn = UIButton(type: .Custom)
    closureBtn.frame = CGRectMake(kMainScreenWidth/2.0+20,150, kMainScreenWidth/2.0 -40, 40)
    closureBtn.setTitle("閉包傳值", forState: .Normal)
    closureBtn.setTitleColor(UIColor.redColor(), forState: .Normal)
    self.view.addSubview(closureBtn)
    closureBtn.addTarget(self, action:Selector("closurePassValueBtnPressed"), forControlEvents: .TouchUpInside)
    // Do any additional setup after loading the view.
}

//MARK: - 代理傳值
func delegatePassValueBtnPressed(){
    delegate?.passValue(textField.text!)
    self.navigationController?.popViewControllerAnimated(true)
}
//MARK: - 閉包傳值
func closurePassValueBtnPressed(){
    if myClosure !=nil {
        myClosure!(newValue: textField.text!)
    }
    self.navigationController?.popViewControllerAnimated(true)
}
override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


/*
// MARK: - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    // Get the new view controller using segue.destinationViewController.
    // Pass the selected object to the new view controller.
}
*/

}