didFinishPickingMediaWithInfo没有在Xcode 12中调用

如何解决didFinishPickingMediaWithInfo没有在Xcode 12中调用

我已经在 UIImagePickerController 上工作。该代码在 Xcode 11.3 中已经可以正常使用。但是当我在Xcode 12上运行时，图像选择器 delegate 没有调用 Xcode12 。

/// Picked Image
struct PickedImage {
    var image: UIImage?
    var api: String?
}

/// Image picker
class ImagePicker: NSObject {
        
    typealias ImagePickerHandler = ((_ selected: PickedImage) -> ())
    
    private weak var presentationController: UIViewController?
    
    let pickerController: UIImagePickerController = UIImagePickerController()

    var apiKey: String?
    
    private var handler: ImagePickerHandler? = nil
    
    private func action(for type: UIImagePickerController.SourceType,title: String) -> UIAlertAction? {
        
        guard UIImagePickerController.isSourceTypeAvailable(type) else {
            return nil
        }
        
        return UIAlertAction(title: title,style: .default) { (action) in
            
            DispatchQueue.main.async {
                
                self.pickerController.mediaTypes = ["public.image"]
                self.pickerController.sourceType = type
                self.pickerController.delegate = self
                
                self.presentationController?.present(self.pickerController,animated: true,completion: {
                })
                
            }
        }
    }
    
    /// Present source view
    /// - Parameter sourceView: view
    func present(presentationController: UIViewController,completed: ImagePickerHandler? = nil) {
        
        self.handler = completed
        
        self.presentationController = presentationController
        // self.delegate = delegate
        
        let alertController = UIAlertController(title: nil,message: nil,preferredStyle: .actionSheet)
        
        if let action = self.action(for: .camera,title: "Take photo") {
            alertController.addAction(action)
        }
        if let action = self.action(for: .savedPhotosAlbum,title: "Camera roll") {
            alertController.addAction(action)
        }
        if let action = self.action(for: .photoLibrary,title: "Photo library") {
            alertController.addAction(action)
        }
        
        alertController.addAction(UIAlertAction(title: "Cancel",style: .cancel,handler: nil))
        
        //            if UIDevice.current.userInterfaceIdiom == .pad {
        //                alertController.popoverPresentationController?.sourceView = sourceView
        //                alertController.popoverPresentationController?.sourceRect = sourceView.bounds
        //                alertController.popoverPresentationController?.permittedArrowDirections = [.down,.up]
        //            }
        self.presentationController?.present(alertController,animated: true)
        
    }
    
    private func pickerController(didSelect image: UIImage?,imageURL: URL?) {
        
        pickerController.dismiss(animated: true,completion: nil)
        // self.delegate?.imagePicker(picker: self,didSelected: image,apikey: apiKey)
        
        handler?(PickedImage(image: image,api: apiKey))
    }
}

/// ImagePicker controller delegate
extension ImagePicker: UIImagePickerControllerDelegate,UINavigationControllerDelegate {
    
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        
        self.pickerController(didSelect: nil,imageURL: nil)
    }
    
    func imagePickerController(_ picker: UIImagePickerController,didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        
        self.pickerController(didSelect: info[.originalImage] as? UIImage,imageURL: info[.imageURL] as? URL)
    }
}

当我检查委托是否已应用或未使用断点时。就像在控制台中一样

po imagepicker.delegate 

之后，图像选择器委托工作正常。但是当我删除断点时，它的委托人没有打电话。

我不知道是什么原因。为什么它不起作用。我可以知道如何解决这个问题。

解决方法

是否有理由不将pickerController.delegate = self放在self.presentationController?.present(pickerController,animated: true,completion: {})'之前？

如果否，也许您可​​以在此之前放pickerController.delegate = self，然后重试。

,

这很可能是因为您没有将选择器控制器保留在变量中。函数完成后，将立即释放该函数。

例如，我有这样的东西：

class MyClass: UIImagePickerControllerDelegate {
   let imagePicker = UIImagePickerController()
}

func pickImageFromGallery() {
    self.imagePicker.delegate = self
    self.imagePicker.sourceType = UIImagePickerController.SourceType.photoLibrary
    self.imagePicker.allowsEditing = false
    self.present(self.imagePicker,completion: nil)
}

... and the delegate methods as well

,

我认为您犯了一个愚蠢的错误。只需更改几行代码，然后您就可以开始了。

只需按照我的步骤

=>这里ProfileViewController是我的UIViewController，我将在其中从Gallery中选择Image并将Image设置为UIImageView。您必须在要拾取图像的地方使用UIViewController。

<div id="products-container">
  <select>
  </select>
  <input type="text">
</div>

ProfileViewController: UIViewController{

let pickerController = UIImagePickerController()

viewDidLoad(){

}

@IBAction func pickImageAction(sender: UIButton){
 self.openImagePicker()
}

func openImagePicker()
{
pickerController.delegate = self
pickerController.allowsEditing = true
pickerController.mediaTypes = ["public.image","public.movie"]
pickerController.sourceType = .photoLibrary // Pick image from PhotoLibrary  
//pickerController.sourceType = .savedPhotosAlbum // Pick Saved Images
//pickerController.sourceType = .camera  // Click Image using Camera
self.present(pickerController,animated: true)
} //End of setupImagePicker


} // End of ProfileViewController

,

您的代码总是错误的；如果能成功，那真是幸运：

  let pickerController: UIImagePickerController = UIImagePickerController()
  pickerController.mediaTypes = ["public.image"]
  pickerController.sourceType = "Photo library"
  self.presentationController?.present(pickerController,completion: {
      pickerController.delegate = self
  })

更改为：

  let pickerController: UIImagePickerController = UIImagePickerController()
  pickerController.mediaTypes = ["public.image"]
  pickerController.sourceType = .photoLibrary
  pickerController.delegate = self
  self.present(pickerController,animated: true)