如何在Swift 3 iOS 10中创建自定义相册

这可能听起来很重复但是在搜索之后我仍然没有得到Swift 3的预期答案。当我尝试使用addAssets()方法添加资产时创建资源占位符Xcode建议我将assetPlacehoder强制转换为FastEnumeration类型。 当我这样做时，它会导致exception。 有人可以帮帮我吗？

Answer 1

使用此课程并在需要时以及在将图像添加到相册之前请求许可。

 class CustomPhotoAlbum: NSObject { static let albumName = "YourAlbumName" static let sharedInstance = CustomPhotoAlbum() var assetCollection: PHAssetCollection! override init() { super.init() if let assetCollection = fetchAssetCollectionForAlbum() { self.assetCollection = assetCollection return } } func requestAuthorizationHandler(status: PHAuthorizationStatus) { if PHPhotoLibrary.authorizationStatus() == PHAuthorizationStatus.authorized { // ideally this ensures the creation of the photo album even if authorization wasn't prompted till after init was done print("trying again to create the album") self.createAlbum() } else { print("should really prompt the user to let them know it's failed") } } func createAlbum() { PHPhotoLibrary.shared().performChanges({ PHAssetCollectionChangeRequest.creationRequestForAssetCollection(withTitle: CustomPhotoAlbum.albumName) // create an asset collection with the album name }) { success, error in if success { self.assetCollection = self.fetchAssetCollectionForAlbum() } else { print("error \(String(describing: error))") } } } func fetchAssetCollectionForAlbum() -> PHAssetCollection? { let fetchOptions = PHFetchOptions() fetchOptions.predicate = NSPredicate(format: "title = %@", CustomPhotoAlbum.albumName) let collection = PHAssetCollection.fetchAssetCollections(with: .album, subtype: .any, options: fetchOptions) if let _: AnyObject = collection.firstObject { return collection.firstObject } return nil } func save(image: UIImage , completion : @escaping () -> ()) { if assetCollection == nil { return // if there was an error upstream, skip the save } PHPhotoLibrary.shared().performChanges({ let assetChangeRequest = PHAssetChangeRequest.creationRequestForAsset(from: image) let assetPlaceHolder = assetChangeRequest.placeholderForCreatedAsset let albumChangeRequest = PHAssetCollectionChangeRequest(for: self.assetCollection) let enumeration: NSArray = [assetPlaceHolder!] if self.assetCollection.estimatedAssetCount == 0 { albumChangeRequest!.addAssets(enumeration) } else { albumChangeRequest!.insertAssets(enumeration, at: [0]) } }, completionHandler: { status , errror in completion( ) }) } } 

在要保存图像的位置调用此方法。

 CustomPhotoAlbum.sharedInstance.save(image: YourImage, completion: { DispatchQueue.main.async(execute: { //"Any UI update should be in main thread." }) })