发现扩展时遇到的 Swift 4 错误 - 照片不会加载到 UI 上

Question

当我从照片库中选择一张照片来填充XCode 9.2中的UIImageView时，我收到以下错误消息：

• [发现] 发现扩展时遇到的错误： 错误域=插件套件代码=13 "查询已取消" 用户信息={NSLocalizedDescription=查询已取消}

模拟器能够访问照片库，我能够查看照片以进行选择，但是当我单击"选择"选项以选择照片时，会抛出错误，并且在选择器被关闭后，图像不会填充UIImageView。

我已经搜索了堆栈溢出，如果我执行此步骤，则可以摆脱错误消息： 从 Xcode 菜单打开：产品>方案> 编辑方案> 在您的环境中 变量设置OS_ACTIVITY_MODE在值集中禁用。 但是，这只能消除错误，并不能解决我所选照片未填充UIImageView的问题。 我是 Swift 和 Xcode 的新手，被困住了！ 请帮忙！

这是我的代码：

import UIKit
class HomeVC: UIViewController, UINavigationControllerDelegate, 
UIImagePickerControllerDelegate {
@IBOutlet weak var avaImg: UIImageView!
@IBOutlet weak var usernameLbl: UILabel!
@IBOutlet weak var fullnameLbl: UILabel!
@IBOutlet weak var emailLbl: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
//get user details from user global var (from database)
let username = (user!["username"] as? String)?.uppercased()
let fullname = user!["fullname"] as? String
let email = user!["email"] as? String
let ava = user!["ava"] as? String
//populate labels on view
usernameLbl.text = username
fullnameLbl.text = fullname
emailLbl.text = email

}
@IBAction func edit_click(_ sender: AnyObject) {
//select ava
let picker = UIImagePickerController()
picker.delegate = self
picker.sourceType = UIImagePickerControllerSourceType.photoLibrary
picker.allowsEditing = true
self.present(picker, animated: true, completion: nil)
//selected image
func imagePickerController(_ picker: UIImagePickerController, 
didFinishPickingMediaWithInfo info: [String : AnyObject]) {
let image = info[UIImagePickerControllerEditedImage] as? 
UIImage
avaImg.image = image
self.dismiss(animated: true, completion: nil)
}
}
}

Answer 1

两个问题：

• didFinishPickingMediaWithInfo的签名是错误的。在 Swift 3+ 中它是

  func imagePickerController(_ picker: UIImagePickerController, 
  didFinishPickingMediaWithInfo info: [String : Any])
  

• 委托方法必须位于类的顶层(而不是在其他方法中)

  @IBAction func edit_click(_ sender: Any) {
  //select ava
  let picker = UIImagePickerController()
  picker.delegate = self
  picker.sourceType = .photoLibrary
  picker.allowsEditing = true
  self.present(picker, animated: true, completion: nil)
  }
  func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
  //selected image
  let image = info[UIImagePickerControllerEditedImage] as? UIImage
  avaImg.image = image
  self.dismiss(animated: true, completion: nil)
  }