我的协议没有调用

Question

I am using protocol for call method but my method does not call.Is there is any example which i use.

Here is my code:

ViewController

    class ViewController: UIViewController {
      override func viewDidLoad() {
        super.viewDidLoad()
                // Do any additional setup after loading the view.
    }


extension ViewController :ViewController1Delegate
{
    func hello()
    {
        println("hbgyguyg");
    }
}

In View Controller 1

import UIKit
@objc
protocol ViewController1Delegate
{
   optional func hello()
}
class ViewController1: UIViewController {
 var delegate: ViewController?
    override func viewDidLoad() {
        super.viewDidLoad()
                    delegate?.hello()
             }

}

Please Help, I am new in Swift.Any help would be apperciated. Thanks in Advance

Answer 1

An example demo.

ViewController file

import UIKit

class ViewController: UIViewController, PopUpViewControllerDelegate
{
    var popupVC: PopUpViewController!;

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

        self.view!.backgroundColor = UIColor.whiteColor();

        self.popupVC = PopUpViewController();
        self.popupVC.delegate = self;


        self.showPopUpVC();
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


    func popUpViewControllerDidPressOK(popUpVC: PopUpViewController) {

        println("Yay?");

        self.closePopUpVC();
    }

    func showPopUpVC()
    {
        let delayTime = dispatch_time(DISPATCH_TIME_NOW,
            Int64(1.0 * Double(NSEC_PER_SEC)))

        dispatch_after(delayTime, dispatch_get_main_queue()) {

            self .presentViewController(self.popupVC, animated: true, completion: nil);

        }
    }

    func closePopUpVC()
    {
        let delayTime = dispatch_time(DISPATCH_TIME_NOW,
            Int64(1.0 * Double(NSEC_PER_SEC)))

        dispatch_after(delayTime, dispatch_get_main_queue()) {

            self.dismissViewControllerAnimated(true, completion: nil);

        }
    }
}

PopUpViewController file

import UIKit

protocol PopUpViewControllerDelegate
{
    func popUpViewControllerDidPressOK(popUpVC: PopUpViewController);
}

class PopUpViewController: UIViewController {

    var delegate: PopUpViewControllerDelegate!;

    override func viewDidLoad() {
        super.viewDidLoad()

        self.view!.backgroundColor = UIColor.redColor();

        // Do any additional setup after loading the view.

        self.delegate!.popUpViewControllerDidPressOK(self);
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}

Notice how in my ViewController viewDidLoad() method, I have a line that initialises the popUp view controller and then set its delegate to be the ViewController itself:

self.popupVC = PopUpViewController();
self.popupVC.delegate = self; // you're missing this line I believe ?

I don't use Interface Builder or Storyboard but maybe select your VC1 in your Storyboard and look in the connections inspector to see if you drag a line from "delegate" to your ViewController file owner thing.

In the end, you should see a red screen popup after 1 second, followed by the word "Yay?" logged into your Xcode console and finally the popupVC dismisses.