Swift语言实现代理传值

最新推荐文章于 2024-07-27 03:56:31 发布

转载最新推荐文章于 2024-07-27 03:56:31 发布 · 41 阅读

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原文链接：http://www.cnblogs.com/gcczhongduan/p/4291248.html

本文介绍如何通过代理模式在iOS应用中实现两个视图控制器间的数据传递，具体通过点击第二个视图控制器中的按钮来改变第一个视图控制器中Label的内容。

需求：利用代理实现反响传值（下面样例採用点击第二个视图控制器中的button来改变第一个视图控制器中的Label的内容）

一、创建RootViewController

import Foundation
import UIKit

class RootViewController:UIViewController,ChangeWordDelegate{
    var qzLabel:UILabel?
    override func viewDidLoad(){
        super.viewDidLoad()
        self.title = "RootViewController"
        let rightBtn:UIBarButtonItem = UIBarButtonItem(title:"下一页",style:.Plain,target:self,action:"nextPage")
        self.navigationItem.rightBarButtonItem = rightBtn
        
        let rect = CGRect(x:0,y:200,width:320,height:50)
        qzLabel = UILabel(frame:rect)
        qzLabel!.text = "秦志伟"
        qzLabel!.textAlignment = NSTextAlignment.Center
        self.view.addSubview(qzLabel)
        
        
    }
    func nextPage(){
        let svc = SecondViewController()
        svc.delegate = self
        self.navigationController.pushViewController(svc,animated:true)
    }
    func changeWord(controller:SecondViewController,string:String){
        qzLabel!.text = string
        println("qzLabel.text == \(string)")
    }
}

二、创建SecondViewController

import Foundation
import UIKit

//定义协议改变Label内容
protocol ChangeWordDelegate:NSObjectProtocol{
    //回调方法
    func changeWord(controller:SecondViewController,string:String)
}
class SecondViewController:UIViewController{
    var temp = 0
    var delegate:ChangeWordDelegate?
    override func viewDidLoad(){
        super.viewDidLoad()
        self.title = "SecondViewController"
        self.view.backgroundColor = UIColor.greenColor()
        let rect = CGRect(x:50,y:200,width:150,height:50)
        var myButton = UIButton(frame:rect)
        myButton.center = CGPointMake(160,200)
        myButton.setTitle("改变Label内容",forState:.Normal)
        myButton.addTarget(self,action:"btnClicked",forControlEvents:.TouchUpInside)
        self.view.addSubview(myButton)
        
    }
    func btnClicked(){
        temp++
        println("我被点击了！")
        if(delegate){
            delegate?.changeWord(self,string:"秦志伟"+String(temp))
        }
        
    }
}

转载于:https://www.cnblogs.com/gcczhongduan/p/4291248.html