没有为 UIimagePickerController 调用委托方法

Question

我正在尝试创建协议，根据用户的选择，我可以使用相机或媒体库打开 UIimagePickerController。

这是一些代码：

import UIKit
protocol PFImagePickerProtocol: UIImagePickerControllerDelegate,UINavigationControllerDelegate where Self: UIViewController {
    func didSelectImage(image: UIImage?, error: Bool)
    func didCancelledImageSelection()
}
extension PFImagePickerProtocol {
    func openImageSelector(withCorp cropEnabled:Bool)  {
        let alertController = UIAlertController(title: "Action Sheet", message: "What would you like to do?", preferredStyle: .actionSheet)

        let camera = UIAlertAction(title: "Camera", style: .default) { (action) in
            self.openImagePicker(withCorp: cropEnabled, sourceType: .camera)
        }
        let library = UIAlertAction(title: "Photo Library", style: .default) { (action) in
            self.openImagePicker(withCorp: cropEnabled, sourceType: .photoLibrary)
        }
        alertController.addAction(camera)
        alertController.addAction(library)

        self.present(alertController, animated: true, completion: nil)
    }

    private func openImagePicker(withCorp cropEnabled:Bool, sourceType: UIImagePickerController.SourceType)  {
        let pickerVc = UIImagePickerController()
        pickerVc.allowsEditing = cropEnabled
        pickerVc.sourceType = sourceType
        pickerVc.delegate = self //is this the problem?
        self.present(pickerVc, animated: true, completion: nil)
    }
}

extension PFImagePickerProtocol{
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        self.dismiss(animated: true, completion: nil)
        didCancelledImageSelection()
    }
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        if let image = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
            didSelectImage(image: image, error: false)
            return
        } else {
            didSelectImage(image: nil, error: true)
        }
        self.dismiss(animated: true, completion: nil)
    }
}

因为我运行代码。函数 'didFinishPickingMediaWithInfo' 未被调用。

我发现回答很有用。但如果有什么可以解决这个问题。请在这里分享。

随时对代码发表评论。

Answer 1

请按如下方式编写代码：

protocol PFImagePickerProtocol {
    func didSelectImage(image: UIImage?, error: Bool)
    func didCancelledImageSelection()
}

并如下编写包含委托方法的扩展：

extension YourViewController {
    func openImageSelector(withCorp cropEnabled:Bool)  {
        let alertController = UIAlertController(title: "Action Sheet", message: "What would you like to do?", preferredStyle: .actionSheet)

        let camera = UIAlertAction(title: "Camera", style: .default) { (action) in
            self.openImagePicker(withCorp: cropEnabled, sourceType: .camera)
        }
        let library = UIAlertAction(title: "Photo Library", style: .default) { (action) in
            self.openImagePicker(withCorp: cropEnabled, sourceType: .photoLibrary)
        }
        alertController.addAction(camera)
        alertController.addAction(library)

        self.present(alertController, animated: true, completion: nil)
    }

    private func openImagePicker(withCorp cropEnabled:Bool, sourceType: UIImagePickerController.SourceType)  {
        let pickerVc = UIImagePickerController()
        pickerVc.allowsEditing = cropEnabled
        pickerVc.sourceType = sourceType
        pickerVc.delegate = self //This will set your picker delegate to view controller class & the below extension conforms the delegates.
        self.present(pickerVc, animated: true, completion: nil)
    }
}

extension YourViewController: UIImagePickerControllerDelegate,UINavigationControllerDelegate{
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        self.dismiss(animated: true, completion: nil)
        didCancelledImageSelection()
    }
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        if let image = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
            didSelectImage(image: image, error: false)
            return
        } else {
            didSelectImage(image: nil, error: true)
        }
        self.dismiss(animated: true, completion: nil)
    }
}

我想你可以将以上所有代码写在一个单独的视图控制器中，比如 AbstractViewController，它是 UIViewController 的子 class，并且所有其他具有此功能的视图控制器都有它们的超级 class 作为 AbstractViewController。

class AbstractViewController: UIViewController {
    // Do above code here
}

class OtherViewController: AbstractViewController {
    // Classes that needs to implement the image picker functionality
}

Answer 2

class PFImagePickerManager

 typealias PFImagePickerTarget = UIImagePickerControllerDelegate & UINavigationControllerDelegate 
    class PFImagePickerManager {
        static var shared: PFImagePickerManager = PFImagePickerManager()
        var target: PFImagePickerTarget!
        private init() {}

         func openImageSelector(target: PFImagePickerTarget, shouldCrop: Bool) {
            self.target = target
            let alertController = UIAlertController(title: PFConstants.PFImagePicker.actionSheetTitle, message: kEmptyStr, preferredStyle: .actionSheet)
            let camera = UIAlertAction(title: PFConstants.PFImagePicker.camera, style: .default) { (action) in
                self.openImagePicker(withCorp: shouldCrop, sourceType: .camera)
            }
            let library = UIAlertAction(title: PFConstants.PFImagePicker.photoLibrary, style: .default) { (action) in
                self.openImagePicker(withCorp: shouldCrop, sourceType: .photoLibrary)
            }
            let cancel = UIAlertAction(title: PFConstants.PFImagePicker.cancel, style: .cancel) { (action) in

            }
            alertController.addAction(camera)
            alertController.addAction(library)
            alertController.addAction(cancel)
            if let vc = target as? PFBaseViewController {
                vc.present(alertController, animated: true, completion: nil)
            }
        }

        private func openImagePicker(withCorp cropEnabled:Bool, sourceType: UIImagePickerController.SourceType)  {

            let pickerVc = UIImagePickerController()
            pickerVc.allowsEditing = cropEnabled
            pickerVc.sourceType = sourceType
            pickerVc.delegate = target
            if sourceType == .photoLibrary {
                pickerVc.navigationBar.tintColor = UIColor.appThemePrimaryColor()
            }
            if let vc = target as? PFBaseViewController {
                vc.present(pickerVc, animated: true, completion: nil)
            }

        }

    }

您需要延长 PFImagePickerTarget

extension YourViewController: PFImagePickerTarget {
    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        picker.dismiss(animated: true, completion: nil)
    }
    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
        if let image = info[UIImagePickerControllerOriginalImage] as? UIImage {
            PFViewUtility.dispatchOnMainThread {
                self.VMCreateGR.changeDatafor(.image, data: image)
                self.tblInputs.reloadData()
            }
        } else {
            self.view.makeToast("Error while selecting image. Please try again.")
        }
        picker.dismiss(animated: true, completion: nil)
    }
}

并在 ViewController 中启动图像选择器

    class AnyViewController: UIViewController {
        // In some method like viewDidLoad call the below line
        PFImagePickerManager.shared.openImageSelector(target: self, shouldCrop: true)
    }

没有为 UIimagePickerController 调用委托方法

delegate method doesn't get called for UIimagePickerController

uiimagepickercontroller

swift-protocols

protocol-oriented

swift4