如何在Swift中从相机或照片库加载图像

Question

如何在Swift中从相机或照片库加载图像

4

如何使用相机拍照或从照片库中选择图像，并能够在imageView中显示它？

如果有任何帮助，将不胜感激。

- Dimitre Bogdanov

我为你发布了一个答案，但是你得到了所有的踩因为这不是“为你编写代码”的网站。你必须提供代码，我们帮助你找错误并改进你的代码。所以下一次尝试通过Google解决方案并在卡住时寻求帮助。现在：我已经完全为你发布了一个有效的选项。玩得开心。 - David Seek

1

我明白这不是让别人替我完成工作的地方，我只是想知道从哪里开始。我并不指望有人为我写出来，但我很感激你发表的答案。 - Dimitre Bogdanov

1

我并不想冒犯你，伙计。只是想告诉你为什么你收到了这么多的踩。我已经给了你一个赞，所以情况不会太糟。如果我的工作对你有帮助，我很高兴回答你的问题，让你能够检查它。如果你需要进一步的帮助，随时让我知道。 - David Seek

1个回答

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可以查看英文原文，
原文链接

- David Seek · Accepted Answer

完整更新Swift 5+，包括Github Repo

首先，我们想将所有内容组织到一个专用类中。

import MobileCoreServices
import UIKit

class CameraProvider: NSObject {

    enum PhotoLibraryTypes {
        case photoLibrary, savedPhotosAlbum
        var casted: UIImagePickerController.SourceType {
            switch self {
            case .photoLibrary: return UIImagePickerController.SourceType.photoLibrary
            case .savedPhotosAlbum: return UIImagePickerController.SourceType.savedPhotosAlbum
            }
        }
    }

    public typealias SourceType = UIImagePickerController.SourceType
    public typealias ImagePicker = UIImagePickerController
    public typealias Delegate = UINavigationControllerDelegate & UIImagePickerControllerDelegate

    private let delegate: Delegate

    init(delegate: Delegate) {
        self.delegate = delegate
    }

    // MARK: - Public

    public func getImagePicker(source: PhotoLibraryTypes,
                               canEditPhotos: Bool = true,
                               onlyImages: Bool = false) throws -> ImagePicker {

        do {
            return try getBaseController(
                source: source.casted,
                allowsEditing: canEditPhotos,
                onlyImages: onlyImages
            )
        } catch {
            throw error
        }
    }

    public func getCamera(canEditPhotos: Bool = true,
                          onlyImages: Bool = false) throws -> ImagePicker {

        do {
            let picker = try getBaseController(
                source: .camera,
                allowsEditing: canEditPhotos,
                onlyImages: onlyImages
            )

            if UIImagePickerController.isCameraDeviceAvailable(.rear) {
                picker.cameraDevice = .rear
            } else if UIImagePickerController.isCameraDeviceAvailable(.front) {
                picker.cameraDevice = .front
            } else {
                throw "No known camera type available"
            }

            picker.showsCameraControls = true
            return picker
        } catch {
            throw error
        }
    }

    // MARK: - Private

    private func getBaseController(source: SourceType,
                                   allowsEditing: Bool,
                                   onlyImages: Bool) throws -> ImagePicker {

        guard UIImagePickerController.isSourceTypeAvailable(source) else {
            throw "Requested source not available"
        }

        let picker = UIImagePickerController()
        let imageType = kUTTypeImage as String
        picker.sourceType = source
        picker.allowsEditing = allowsEditing
        picker.delegate = self.delegate

        if onlyImages,
           let mediaTypes = UIImagePickerController.availableMediaTypes(for: source),
           mediaTypes.contains(imageType){
            picker.mediaTypes = [imageType]
        }

        return picker
    }
}

extension String: LocalizedError {
    public var errorDescription: String? { return self }
}

最后，我们按以下方式调用 CameraProvider。

import UIKit

class ViewController: UIViewController {
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        let provider = CameraProvider(delegate: self)

        do {
            let picker = try provider.getImagePicker(source: .photoLibrary)
            present(picker, animated: true)
        } catch {
            NSLog("Error: \(error.localizedDescription)")
        }
    }
}

extension ViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        let image = (
            info[UIImagePickerController.InfoKey.editedImage] as? UIImage ??
            info[UIImagePickerController.InfoKey.originalImage] as? UIImage
        )
        picker.dismiss(animated: true, completion: nil)
    }
}