ios - imagePickerController 委托(delegate)未调用，Swift

Question

我有一个个人资料图片，它也充当一个按钮，当人们点击图片时，图像选择器会出现，他们可以选择他们想要用作个人资料图片的图片，但是 imagePickerController 未被调用，并且 Parse db 图像文件未被调用。为什么会发生这种情况，我该如何解决？

class ProfileView: UIViewController,  UIImagePickerControllerDelegate {
 func userchange(sender: AnyObject){
    if UIImagePickerController.isSourceTypeAvailable(UIImagePickerControllerSourceType.SavedPhotosAlbum){
       // imagePicker.delegate = self
        imagePicker.allowsEditing = false
        imagePicker.sourceType = .PhotoLibrary
        presentViewController(imagePicker, animated: true, completion: nil)

    }
}

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
    if let pickedImage = info[UIImagePickerControllerOriginalImage] as? UIImage {

        let user = PFUser.currentUser()
        let image = info[UIImagePickerControllerOriginalImage] as! UIImage
        let imageData = UIImageJPEGRepresentation(image, 0.05)
        let imageFile = PFFile(name:"image.jpg", data:imageData!)
        user!["ProPic"] = imageFile;
        imageFile.save()
        //NOTHING IS BEING PRINTED
        print("called")
        user!.saveInBackgroundWithBlock(nil)


        self.dismissViewControllerAnimated(true, completion: nil)

    }
   }
 }

Answer 1

在 swift 2.0 及以后的版本中，如果您使用任何委托(delegate)，例如 UIImagePickerControllerDelegate，您需要强制实现委托(delegate)方法，否则不要在您的 View Controller 中使用或添加，这是概念，现在遵循这个一些例子

第一步

在您的 View Controller 中添加 UIImagePickerControllerDelegate、UINavigationControllerDelegate

class ViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {

@IBOutlet var imageView: UIImageView!

let imagePicker = UIImagePickerController()

第二步

  override func viewDidLoad() {
super.viewDidLoad()

imagePicker.delegate = self // Its Manotary
}

第三步

 // Present the Image picker controller

@IBAction func loadImageButtonTapped(sender: UIButton) {
imagePicker.allowsEditing = false
imagePicker.sourceType = .PhotoLibrary

presentViewController(imagePicker, animated: true, completion: nil)
}

第四步

// call the delegate method for pick the image

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject]) {
if let pickedImage = info[UIImagePickerControllerOriginalImage] as? UIImage {
    imageView.contentMode = .ScaleAspectFit
    imageView.image = pickedImage
}

dismissViewControllerAnimated(true, completion: nil)
}

第五步

// finally dismiss the Imagepicker controller

func imagePickerControllerDidCancel(picker: UIImagePickerController)    {
dismissViewControllerAnimated(true, completion: nil)
}