swift场景转换2和委托

下面是3个视图控制器，用连线来进行跳转！还有一个是用id来进行跳转。如图选中线设置identifiter属性 ，把<去场景>按钮的identifiter 改成c


写一个A场景的视图控制器

import UIKit

class ViewController: UIViewController {

override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}

override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
//这是id 按钮的关联函数
@IBAction func jumpToB(sender: UIButton) {
//还可以传值
performSegueWithIdentifier("B", sender: "kangkang")
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if(segue.identifier=="B"){

print(sender)
}
else if(segue.identifier=="c"){

print("to  场景")

}

}
}

用委托实现更新数据如下图！点击button去b，然后点传值返回



写一个a场景的视图控制器

import UIkit
class Aviewcontroll:UIViewController{
//var str:String="lable"
@IBOutlet weak var mylabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
print("数据初始化lab:",mylabel.text)
//   mylabel.text= str
// Do any additional setup after loading the view.
}

override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()

}

@IBAction func tojumpB(sender: UIButton) {

let vc = self.storyboard?.instantiateViewControllerWithIdentifier("myAScene") as! BviewControll
vc.delegate=self
presentViewController(vc, animated: true, completion: nil)
}

//说明用上面的方式进行跳转时，不会执行prepareForSegue方法
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
//                let target = segue.destinationViewController as! BviewControll
//                target.delegate = self
}

}
extension Aviewcontroll : BDelegate{
func b(controller: BviewControll, data:String){
print("\(data)")
mylabel.text = data

//    str = data
//        print("数据：",str)
}

}

再写一个b场景的视图控制器

import UIKit

class BviewControll:UIViewController{
var delegate: BDelegate?
override func viewDidLoad() {
super.viewDidLoad()

// Do any additional setup after loading the view.
}

override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()

}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
//      let target = segue.destinationViewController as! Aviewcontroll
//       self.delegate = target

}

@IBAction func jumptoA(sender: UIButton) {
//返回my self data 数据
delegate?.b(self, data:"my self data")
dismissViewControllerAnimated(true, completion: nil)

}

}

再写一个delegate

import Foundation

protocol BDelegate{

//    func someMethod()
//这是为了满足ios开发中委托的标准写法，
//并不是强制要求这样写，简单来说就是为了装逼

//装逼标准：1.名字：delegate前面的内容，
//2.第一个参数是对应的类型
//3.真正需要传递的数据
func b(controll:BviewControll,data:String)

}

这样就可以传值返回了label里就有值了！