ios - 使用 phimagemanager 将图像保存到自定义相册？

Question

我正在制作一个使用 AVFoundation 拍照的应用程序，我想将它们保存到一个自定义相册中，然后我可以在我的应用程序中查询和显示该相册。 (我宁愿不要将它们放在一般的照片卷中，除非用户想要那样)我真的找不到任何显示如何在 Swift 中执行此操作的内容......或根本找不到。我应该采用其他方式来执行此操作吗？

我在 SO 上找到了这个例子，但它对我来说没有意义，我无法让它工作。

    func savePhoto() {
    var albumFound : Bool = false
    var assetCollection: PHAssetCollection!
    var photosAsset: PHFetchResult!
    var assetThumbnailSize:CGSize!

    // Create the album if does not exist (in viewDidLoad)
    if let first_Obj:AnyObject = collection.firstObject{
        //found the album
        self.albumFound = true
        self.assetCollection = collection.firstObject as PHAssetCollection
    }else{
        //Album placeholder for the asset collection, used to reference collection in completion handler
        var albumPlaceholder:PHObjectPlaceholder!
        //create the folder
        NSLog("\nFolder \"%@\" does not exist\nCreating now...", albumName)
        PHPhotoLibrary.sharedPhotoLibrary().performChanges({
            let request = PHAssetCollectionChangeRequest.creationRequestForAssetCollectionWithTitle(albumName)
            albumPlaceholder = request.placeholderForCreatedAssetCollection
            },
            completionHandler: {(success:Bool, error:NSError!)in
                NSLog("Creation of folder -> %@", (success ? "Success":"Error!"))
                self.albumFound = (success ? true:false)
                if(success){
                    let collection = PHAssetCollection.fetchAssetCollectionsWithLocalIdentifiers([albumPlaceholder.localIdentifier], options: nil)
                    self.assetCollection = collection?.firstObject as PHAssetCollection
                }
        })
    }



    let bundle = NSBundle.mainBundle()
    let myFilePath = bundle.pathForResource("highlight1", ofType: "mov")
    let videoURL:NSURL = NSURL.fileURLWithPath(myFilePath!)!

    let priority = DISPATCH_QUEUE_PRIORITY_DEFAULT
    dispatch_async(dispatch_get_global_queue(priority, 0), {
        PHPhotoLibrary.sharedPhotoLibrary().performChanges({
            //let createAssetRequest = PHAssetChangeRequest.creationRequestForAssetFromImage
            let createAssetRequest = PHAssetChangeRequest.creationRequestForAssetFromVideoAtFileURL(videoURL)
            let assetPlaceholder = createAssetRequest.placeholderForCreatedAsset
            let albumChangeRequest = PHAssetCollectionChangeRequest(forAssetCollection: self.assetCollection, assets: self.photosAsset)
            albumChangeRequest.addAssets([assetPlaceholder])
            }, completionHandler: {(success, error)in
                dispatch_async(dispatch_get_main_queue(), {
                    NSLog("Adding Image to Library -> %@", (success ? "Sucess":"Error!"))
                    //picker.dismissViewControllerAnimated(true, completion: nil)
                })
        })

    })
}

任何帮助/解释都会很棒!

Answer 1

我是这样的:

在顶部:

import Photos

var image: UIImage!
var assetCollection: PHAssetCollection!
var albumFound : Bool = false
var photosAsset: PHFetchResult!
var assetThumbnailSize:CGSize!
var collection: PHAssetCollection!
var assetCollectionPlaceholder: PHObjectPlaceholder!

创建相册:

func createAlbum() {
    //Get PHFetch Options
    let fetchOptions = PHFetchOptions()
    fetchOptions.predicate = NSPredicate(format: "title = %@", "camcam")
    let collection : PHFetchResult = PHAssetCollection.fetchAssetCollectionsWithType(.Album, subtype: .Any, options: fetchOptions)
    //Check return value - If found, then get the first album out
    if let _: AnyObject = collection.firstObject {
        self.albumFound = true
        assetCollection = collection.firstObject as! PHAssetCollection
    } else {
        //If not found - Then create a new album
        PHPhotoLibrary.sharedPhotoLibrary().performChanges({
            let createAlbumRequest : PHAssetCollectionChangeRequest = PHAssetCollectionChangeRequest.creationRequestForAssetCollectionWithTitle("camcam")
            self.assetCollectionPlaceholder = createAlbumRequest.placeholderForCreatedAssetCollection
            }, completionHandler: { success, error in
                self.albumFound = success

                if (success) {
                    let collectionFetchResult = PHAssetCollection.fetchAssetCollectionsWithLocalIdentifiers([self.assetCollectionPlaceholder.localIdentifier], options: nil)
                    print(collectionFetchResult)
                    self.assetCollection = collectionFetchResult.firstObject as! PHAssetCollection
                }
        })
    }
}

保存照片时:

func saveImage(){
        PHPhotoLibrary.sharedPhotoLibrary().performChanges({
            let assetRequest = PHAssetChangeRequest.creationRequestForAssetFromImage(self.image)
            let assetPlaceholder = assetRequest.placeholderForCreatedAsset
            let albumChangeRequest = PHAssetCollectionChangeRequest(forAssetCollection: self.assetCollection, assets: self.photosAsset)
            albumChangeRequest!.addAssets([assetPlaceholder!])
            }, completionHandler: { success, error in
                print("added image to album")
                print(error)

                self.showImages()
        })
    }

显示该相册中的图像:

func showImages() {
        //This will fetch all the assets in the collection

        let assets : PHFetchResult = PHAsset.fetchAssetsInAssetCollection(assetCollection, options: nil)
        print(assets)

        let imageManager = PHCachingImageManager()
        //Enumerating objects to get a chached image - This is to save loading time
        assets.enumerateObjectsUsingBlock{(object: AnyObject!,
            count: Int,
            stop: UnsafeMutablePointer<ObjCBool>) in

            if object is PHAsset {
                let asset = object as! PHAsset
                print(asset)

                let imageSize = CGSize(width: asset.pixelWidth, height: asset.pixelHeight)

                let options = PHImageRequestOptions()
                options.deliveryMode = .FastFormat

                imageManager.requestImageForAsset(asset, targetSize: imageSize, contentMode: .AspectFill, options: options, resultHandler: {(image: UIImage?,
                    info: [NSObject : AnyObject]?) in
                    print(info)
                    print(image)
                })
            }
        }