我正在开发一个iPhone照片应用程序，所以我需要在相机胶卷中创建一个名为“My Album”的单独相册，我需要在新创建的目录中保存带有自定义名称的UIImageView图像，例如“My Image.png” 。
我怎样才能做到这一点？
您可以使用iOS中的以下代码行创建自定义相册并轻松添加图像：
// Create the new album.
__block PHObjectPlaceholder *myAlbum;
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
PHAssetCollectionChangeRequest *changeRequest = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:title];
myAlbum = changeRequest.placeholderForCreatedAssetCollection;
} completionHandler:^(BOOL success, NSError *error) {
if (success) {
PHFetchResult *fetchResult = [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[myAlbum.localIdentifier] options:nil];
PHAssetCollection *assetCollection = fetchResult.firstObject;
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
PHAssetChangeRequest *assetChangeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image];
// add asset
PHAssetCollectionChangeRequest *assetCollectionChangeRequest = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:assetCollection];
[assetCollectionChangeRequest addAssets:@[[assetChangeRequest placeholderForCreatedAsset]]];
} completionHandler:^(BOOL success, NSError *error) {
if (!success) {
NSLog(@"Error: %@", error);
}
}];
} else {
NSLog(@"Error: %@", error);
}
}];
由于AssetsLibrary已被弃用，请使用Photos框架（iOS 8及更高版本）。
// Deprecated!
import AssetsLibrary
// Swift 3.0
let assetsLibrary = ALAssetsLibrary()
assetsLibrary.addAssetsGroupAlbum(withName: "NewAlbum", resultBlock: { assetsGroup in
print(assetsGroup == nil ? "Already created" : "Success")
}, failureBlock: { error in
print(error)
})
您可以使用共享的PHPhotoLibrary对象来创建新照片，但是您无法为它们指定具体名称，因为您将使用需要由Photos.app管理的资产。每个资产都有特定的属性。您可以获取对象，请求更改，资产/缩略图加载和缓存等。
要创建自定义相册，请使用PHAssetCollectionChangeRequest.creationRequestForAssetCollection(withTitle:)。
简要示例：
// Swift 3.0
func createPhotoLibraryAlbum(name: String) {
var albumPlaceholder: PHObjectPlaceholder?
PHPhotoLibrary.shared().performChanges({
// Request creating an album with parameter name
let createAlbumRequest = PHAssetCollectionChangeRequest.creationRequestForAssetCollection(withTitle: name)
// Get a placeholder for the new album
albumPlaceholder = createAlbumRequest.placeholderForCreatedAssetCollection
}, completionHandler: { success, error in
if success {
guard let placeholder = albumPlaceholder else {
fatalError("Album placeholder is nil")
}
let fetchResult = PHAssetCollection.fetchAssetCollections(withLocalIdentifiers: [placeholder.localIdentifier], options: nil)
guard let album: PHAssetCollection = fetchResult.firstObject else {
// FetchResult has no PHAssetCollection
return
}
// Saved successfully!
print(album.assetCollectionType)
}
else if let e = error {
// Save album failed with error
}
else {
// Save album failed with no error
}
})
}
别忘了import Photos图书馆。
要在该相册上创建新的照片资源，请使用PHAssetCollectionChangeRequest.creationRequestForAssetCollection(withTitle:)。
// Swift 3.0
func createPhotoOnAlbum(photo: UIImage, album: PHAssetCollection) {
PHPhotoLibrary.shared().performChanges({
// Request creating an asset from the image
let createAssetRequest = PHAssetChangeRequest.creationRequestForAsset(from: photo)
// Request editing the album
guard let albumChangeRequest = PHAssetCollectionChangeRequest(for: album) else {
// Album change request has failed
return
}
// Get a placeholder for the new asset and add it to the album editing request
guard let photoPlaceholder = createAssetRequest.placeholderForCreatedAsset else {
// Photo Placeholder is nil
return
}
albumChangeRequest.addAssets([photoPlaceholder] as NSArray)
}, completionHandler: { success, error in
if success {
// Saved successfully!
}
else if let e = error {
// Save photo failed with error
}
else {
// Save photo failed with no error
}
})
}
更新：
我们需要请求访问才能使用照片库：
PHPhotoLibrary.requestAuthorization { status in
switch status {
...
}
从iOS 10及更高版本开始，我们还需要在目标.plist文件中为“隐私 - 照片库使用说明”添加访问条目：
<key>NSPhotoLibraryUsageDescription</key>
<string>Access to photos is needed to provide app features</string>
它从iOS 5.0开始运行。 请导入AssetsLibrary / AssetsLibrary.h
ALAssetsLibrary* libraryFolder = [[ALAssetsLibrary alloc] init];
[libraryFolder addAssetsGroupAlbumWithName:@"My Album" resultBlock:^(ALAssetsGroup *group)
{
NSLog(@"Adding Folder:'My Album', success: %s", group.editable ? "Success" : "Already created: Not Success");
} failureBlock:^(NSError *error)
{
NSLog(@"Error: Adding on Folder");
}];
制作新相册：
func createAlbum(withTitle title: String, completionHandler: @escaping (PHAssetCollection?) -> ()) {
DispatchQueue.global(qos: .background).async {
var placeholder: PHObjectPlaceholder?
PHPhotoLibrary.shared().performChanges({
let createAlbumRequest = PHAssetCollectionChangeRequest.creationRequestForAssetCollection(withTitle: title)
placeholder = createAlbumRequest.placeholderForCreatedAssetCollection
}, completionHandler: { (created, error) in
var album: PHAssetCollection?
if created {
let collectionFetchResult = placeholder.map { PHAssetCollection.fetchAssetCollections(withLocalIdentifiers: [$0.localIdentifier], options: nil) }
album = collectionFetchResult?.firstObject
}
completionHandler(album)
})
}
}
获取具有指定名称的相册：
func getAlbum(title: String, completionHandler: @escaping (PHAssetCollection?) -> ()) {
DispatchQueue.global(qos: .background).async { [weak self] in
let fetchOptions = PHFetchOptions()
fetchOptions.predicate = NSPredicate(format: "title = %@", title)
let collections = PHAssetCollection.fetchAssetCollections(with: .album, subtype: .any, options: fetchOptions)
if let album = collections.firstObject {
completionHandler(album)
} else {
self?.createAlbum(withTitle: title, completionHandler: { (album) in
completionHandler(album)
})
}
}
}
并将照片保存到相册：
func save(photo: UIImage, toAlbum titled: String completionHandler: @escaping (Bool, Error?) -> ()) {
getAlbum(title: titled) { (album) in
DispatchQueue.global(qos: .background).async {
PHPhotoLibrary.shared().performChanges({
let assetRequest = PHAssetChangeRequest.creationRequestForAsset(from: photo)
let assets = assetRequest.placeholderForCreatedAsset
.map { [$0] as NSArray } ?? NSArray()
let albumChangeRequest = album.flatMap { PHAssetCollectionChangeRequest(for: $0) }
albumChangeRequest?.addAssets(assets)
}, completionHandler: { (success, error) in
completionHandler(success, error)
})
}
}
}
您可以尝试我的以下方法为iOS 7和iOS 8创建相册
#define PHOTO_ALBUM_NAME @"AlbumName Videos"
-(void)createAlbum{
// PHPhotoLibrary_class will only be non-nil on iOS 8.x.x
Class PHPhotoLibrary_class = NSClassFromString(@"PHPhotoLibrary");
if (PHPhotoLibrary_class) {
// iOS 8..x. . code that has to be called dynamically at runtime and will not link on iOS 7.x.x ...
[[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
[PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:PHOTO_ALBUM_NAME];
} completionHandler:^(BOOL success, NSError *error) {
if (!success) {
NSLog(@"Error creating album: %@", error);
}else{
NSLog(@"Created");
}
}];
}else{
[self.library addAssetsGroupAlbumWithName:PHOTO_ALBUM_NAME resultBlock:^(ALAssetsGroup *group) {
NSLog(@"adding album:'Compressed Videos', success: %s", group.editable ? "YES" : "NO");
if (group.editable == NO) {
}
} failureBlock:^(NSError *error) {
NSLog(@"error adding album");
}];
}}