我想将资产从一张专辑转移到另一张专辑。但我只能找到有关创建和删除资产的信息。我想移动而不是创建新副本并删除旧副本的原因是，我想保留资产的level = int(input('Please enter your pokemons level :' ))
Attackstat= int(input('Please enter your pokemons special/attack stat : '))
Defensestat= int(input('Please enter your opponents special/defense stat : '))
Attackpower= int(input('Please enter your moves base attack : '))
answer= str('Is your move STAB? : ')
STAB= if answer == yes:
STAB= 1.5
else:
STAB= 1
answer1= int('How effective is your move?')
resistance= if answer1== 4:
resistance= 4
if answer1== 2:
resistance= 2
if answer1== 1:
resistance= 1
if answer1== 0.5:
resistance= 0.5
if answer1== 0.25:
resistance= 0.25
damage= (((2* level/5 +2) * Attackstat * Attackpower/ Defensestat)/50)+2)*STAB*resistance/100
print (damage)
等数据位。如果我在另一个相册中重新创建资源，系统会为其分配一个新的localIdentifier，我是对的吗？
但似乎不可能。所以我至少要复制资产。但它也给我带来了麻烦。
这是我的代码。
localIdentifier应用程序在func copyAsset() {
if let assets = getAssetsFromCollection(collectionTitle: "Old") {
if getAssetColection("New") == nil {
createCollection("New") { collection in
if let collection = collection {
print("Collection created")
self.copyAssetsToCollection(assets, toCollection: collection)
}
}
}
}
}
/**
Copy assets to album.
- parameter assets: Array of assets to copy.
- parameter collection: The collection where the assets need to be copied.
*/
func copyAssetsToCollection(assets: [PHAsset], toCollection collection: PHAssetCollection) {
PHPhotoLibrary.sharedPhotoLibrary().performChanges({
let asset = assets.first!
print(asset.localIdentifier)
let assetChangeRequest = PHAssetChangeRequest(forAsset: asset)
let assetPlaceholder = assetChangeRequest.placeholderForCreatedAsset!
let collectionChangeRequest = PHAssetCollectionChangeRequest(forAssetCollection: collection)!
collectionChangeRequest.addAssets([assetPlaceholder])
}, completionHandler: { success, error in
if success {
print("Photo copied to collection")
} else {
if let error = error {
print("Error adding photos to collection: \(error.code) - \(error.localizedDescription)")
}
}
})
}
/**
Retrieve the album for the given title.
- parameter title: Album title.
- returns: Album if it exists. nil if it doesn't.
*/
func getAssetColection(title: String) -> PHAssetCollection? {
let fetchOptions = PHFetchOptions()
fetchOptions.predicate = NSPredicate(format: "title ==[cd] %@", title)
if let collection = PHAssetCollection.fetchAssetCollectionsWithType(.Album, subtype: .AlbumRegular, options: fetchOptions).firstObject {
return collection as? PHAssetCollection
}
return nil
}
/**
Get assets from a given album.
- parameter title: Album title.
- returns: An array of assets if they exist. nil if they don't.
*/
func getAssetsFromCollection(collectionTitle title: String) -> [PHAsset]? {
var assets = [PHAsset]()
if let collection = getAssetColection(title) {
let fetchOptions = PHFetchOptions()
fetchOptions.predicate = NSPredicate(format: "mediaType == %d", PHAssetMediaType.Image.rawValue)
let fetchResult = PHAsset.fetchAssetsInAssetCollection(collection, options: fetchOptions)
fetchResult.enumerateObjectsUsingBlock { object, index, stop in
if let asset = object as? PHAsset {
assets.append(asset)
}
}
return assets
}
return nil
}
/**
Create an album in Photos app.
- parameter title: Album title.
- parameter completion: Album if successfully created. nil if it fails.
*/
func createCollection(title: String, completion: (collection: PHAssetCollection?) -> ()) {
var albumPlaceholder: PHObjectPlaceholder!
PHPhotoLibrary.sharedPhotoLibrary().performChanges({
let request = PHAssetCollectionChangeRequest.creationRequestForAssetCollectionWithTitle(title)
albumPlaceholder = request.placeholderForCreatedAssetCollection
}, completionHandler: { success, error in
if success {
let fetchResult = PHAssetCollection.fetchAssetCollectionsWithLocalIdentifiers([albumPlaceholder.localIdentifier], options: nil)
completion(collection: fetchResult.firstObject as? PHAssetCollection)
} else {
if let error = error {
print("Failed to create album: \(title) in Photos app: \(error.code) - \(error.localizedDescription)")
completion(collection: nil)
}
}
})
}
行崩溃，以查找let assetPlaceholder = assetChangeRequest.placeholderForCreatedAsset!的{{1}}值。这意味着nil只能用于更改资源的元数据而不能复制它。
还有其他办法吗？任何变通方法或黑客攻击？我真的很感激任何帮助。
答案 0 :(得分：1)
将资产从一个专辑复制到另一个专辑没有任何意义：在iOS照片库中，所有原始照片/视频都位于＆＃34;所有照片＆＃34; /＆＃34;相机胶卷＆＃34;。相册仅包含对位于＆＃34;所有照片/相机胶卷＆＃34;中的原始照片/视频的引用。这意味着您可以将一张照片分配给n-Albums。要管理这些作业，请查看PHAssetCollectionChangeRequest课程。要在相册中添加一个或多个照片/视频，请使用addAssets:，使用removeAssets:方法从相册中删除资源。