无法下标类型'[String：Any]'的值，其索引类型为'UIImagePickerController.InfoKey'

Question

我正在使用Apple's Swift iOS Tutorial。这是一个错误，

无法下标类型'[String：Any]'的值，其索引类型为'UIImagePickerController.InfoKey'

他们定义的功能如下。

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

    // The info dictionary may contain multiple representations of the image. You want to use the original.
    guard let selectedImage = info[UIImagePickerControllerOriginalImage] as? UIImage else {
        fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
    }

    // Set photoImageView to display the selected image.
    photoImageView.image = selectedImage

    // Dismiss the picker.
    dismiss(animated: true, completion: nil)
}

我正在使用Xcode Version 10.0 beta 3，其中包括Swift 4.2。

我想了解如何遍历文档以了解可能已发生变化或破坏的内容。

Answer 1

Swift 4.2中该方法的签名已更改

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

你必须写

guard let selectedImage = info[.originalImage] as? UIImage else {
    fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
}

您可以通过阅读documentation或通过注释掉整个方法来自己弄清楚这些术语的变化，重新键入前几个字符并使用代码完成。

Answer 2

我也遵循相同的教程，更新的代码如下所示：

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

    // The info dictionary may contain multiple representations of the image. You want to use the original.
    guard let selectedImage = info[.originalImage] as? UIImage else {
        fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
    }

    // Set photoImageView to display the selected image.
    photoImageView.image = selectedImage

    // Dismiss the picker.
    dismiss(animated: true, completion: nil)
}

Answer 3

像这样使用，

guard let selectedImage = info[UIImagePickerController.InfoKey.originalImage.rawValue] as? UIImage else {
        fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
}

Answer 4

在Swift 4和5中如下：

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

    guard let selectedImage = info[.editedImage] as? UIImage else {
        fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
    }

    self.myImageView.image = selectedImage

    picker.dismiss(animated: true, completion: nil)
}

Answer 5

斯威夫特5

在最新版本的swift 4或5中，委托方法如下，它应该可以工作

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    // Code here
}

并使用，

guard let selectedImage = info[.editedImage] as? UIImage else {

}

Answer 6

方法在Swift 4.2中有所改变。

首先初始化这两个变量：

var imagePicker = UIImagePickerController()
var pickedImageProduct = UIImage()

extension yourViewController: UIImagePickerControllerDelegate,UINavigationControllerDelegate{
//create an IBAction to access Camera
    @IBAction func accessCameraBtn(_ sender: UIButton) {
        imagePicker.delegate = self
        imagePicker.sourceType = UIImagePickerController.SourceType.camera
        self.present(imagePicker, animated: true, completion: nil)
    }
//create an IBAction to access Gallery
    @IBAction func accessGalleryBtn(_ sender: UIButton) {
        imagePicker.delegate = self
        imagePicker.sourceType = UIImagePickerController.SourceType.photoLibrary
        self.present(imagePicker, animated: true, completion: nil)
    }
//Final step put this Delegate    
    func imagePickerController(_ picker: UIImagePickerController,
                               didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

        guard let selectedImage = info[.originalImage] as? UIImage else {
           Print("Error: \(info)")
        }

            pickedImageProduct = selectedImage

        dismiss(animated: true, completion: nil)
     }
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {

        dismiss(animated: true, completion: nil)
    }

}

Answer 7

在Swift 4.2中，您可以将函数编写为：

    func photoLib()
    {
        //opens Photo Library, call the function in a @IBAction func
        let myPickerController = UIImagePickerController()
        myPickerController.delegate = self;
        myPickerController.sourceType = 
        UIImagePickerController.SourceType.photoLibrary
        myPickerController.allowsEditing = true
        present(myPickerController, animated: true)
    }


    func imagePickerController(_ picker: UIImagePickerController, 
    didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    picker.dismiss(animated: true)

    guard let image = info[.editedImage] as? UIImage else {
        print("No image found")
        photoLabel.text = "Photo Not Found"
        return
    }
}