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的Swift iOS教程.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)")
}

您可以通过阅读文档或注释掉整个方法来自己找出这些术语更改,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

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

迅捷5

在最新版本的swift 4或5中，下面给出了委托方法，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 {

}



func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    guard let selectedImage = info[.editedImage] as? UIImage else {

    }
}

Answer 5

在Swift 4和5中，如下所示：

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)
}