I want to implement an action that starts when the camera screen switches after shooting.

import UIKit

classViewController: UIViewController, UIImagePickerControllerDelegate, 
 US>UINavigationControllerDelegate{

override func viewDidLoad(){
        super.viewDidLoad()
   let myImage=UIImage(named: "ume")
            um.image=myImage
  }

@IBOutlet weak varyagi: UIImageView!

@ IBAction funclaunchCamera (sender: UIButton) {

let camera = UIImagePickerControllerSourceType.Camera

if UIImagePickerController.isSourceTypeAvailable(camera){
letpicker=UIImagePickerController()
picker.sourceType=camera
picker.delegate=self
self.presentViewController(picker, animated:true, completion:nil)
  }

funcimagePickerController(picker:UIImagePickerController, 
 DidFinishPickingMediaWithInfo: [String:AnyObject]) {

let image=info [UIImagePickerControllerOriginalImage] as!UIImage
UIImageWriteToSavedPhotosAlbum (image, nil, nil, nil)
self.dismissViewControllerAnimated(true, completion:nil)

yagi.hidden=true;

   }
  } 

}