SwiftUI 保存图片到相册

本文描述了在 SwiftUI 应用中如何保存图片到相册

前提条件

1. 从相册读取照片

实现步骤 iOS16+

声明权限

在 Info.plist 文件中增加. 注意, 必须提供一个具体的使用例子, 不然可能会被 App Store 审核人员拒绝. Guideline 5.1.1 - Legal - Privacy - Data Collection and Storage

<key>NSPhotoLibraryAddUsageDescription</key>
<string>The app needs access to your photo library to save images, such as the Ghibli-style image generated by the app.</string>

定义 MediaSaver

import Photos

struct MediaSaver {
    static func saveImageToPhotoLibrary(url: URL) async throws {
        try await PHPhotoLibrary.shared().performChanges {
            PHAssetCreationRequest.creationRequestForAssetFromImage(atFileURL: url)
        }
    }
    
    static func saveVideoToPhotoLibrary(url: URL) async throws {
        try await PHPhotoLibrary.shared().performChanges {
            PHAssetCreationRequest.creationRequestForAssetFromVideo(atFileURL: url)
        }
    }
}

使用 MediaSaver

Task {
    do {
        try await MediaSaver.saveVideoToPhotoLibrary(url: videoURL)
    } catch {
        print(error.localizedDescription)
    }
}

实现步骤 iOS15+

声明权限

在 Info.plist 文件中增加

<key>NSPhotoLibraryAddUsageDescription</key>
<string>The App want save images to the Photo Library</string>

定义 ImageSaver

// ImageSaver.swift
import UIKit

class ImageSaver: NSObject {
    var successHandler: (() -> Void)?
    var errorHandler: ((Error) -> Void)?

    func writeToPhotoAlbum(image: UIImage) {
        UIImageWriteToSavedPhotosAlbum(image, self, #selector(saveCompleted), nil)
    }

    @objc func saveCompleted(_ image: UIImage, didFinishSavingWithError error: Error?, contextInfo: UnsafeRawPointer) {
        if let error = error {
            errorHandler?(error)
        } else {
            successHandler?()
        }
    }
}

使用 ImageSaver

// ContentView.swift

func savePhoto() {
    guard let processedImage = processedImage else { return }

    let imageSaver = ImageSaver()

    imageSaver.successHandler = {
        print("Success!")
    }

    imageSaver.errorHandler = {
        print("Oops! \($0.localizedDescription)")
    }

    imageSaver.writeToPhotoAlbum(image: processedImage)
}