从图库或相机中选择图像后，UIImage 未显示

Question

我正在尝试从相机或图库中选择图像，并在我的图像视图中将所选图像显示到屏幕上。但它没有显示。

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

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

        imageview.image = selectedImage

        dismiss(animated: true, completion: nil)
    }

我错过了什么？

就我而言，断点函数根本没有调用

Answer 1

如果你的断点函数没有在调用，那么我认为你没有在 viewDidLoad() 中设置 imagePicker 委托

override func viewDidLoad() {
     super.viewDidLoad()
     imagePicker.delegate = self   
   }

Answer 2

我之前遇到过同样的问题，并通过设置延迟图像来解决它，如下所示：

DispatchQueue.main.asyncAfter(deadline: .now() + 1.0, execute: {
    self.imageview.image = selectedImage
})

希望这会有所帮助。

Answer 3

确保您已将 UIImagePickerControllerDelegate 添加到您的班级并设置了您的 UIImagePickerController 实例委托：

class PickerViewController: UIViewController, UIImagePickerControllerDelegate {
    var pickerController = UIImagePickerController()

    override func viewDidLoad() {
        super.viewDidLoad()
        pickerController.delegate = self
    }
}

另外，最好关闭发送给此委托的picker 参数：

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

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