如何从照片，iOS SDK的自定义相册中获取图像？
我正在开发一个iOS应用程序，其中需要像Instagram一样的图库视图。 我已经添加了画廊查看，相机视图和video查看，拍摄后它保存到自定义相册的照片。 现在，我想从自定义相册中检索这些图像，并将其显示到图库的“collections”视图。 但是，我陷入从自定义相册中检索这些图像。 任何帮助将不胜感激。 
编辑：我添加了PHPhotoLibrary创build自定义相册，在此之前，我添加了AssetsLibrary框架。
然后，我创build了一个NSObject类（CustomAlbum），用于使用PHPhotoLibrary创build和pipe理自定义相册。
// CustomAlbum.h
#import <Foundation/Foundation.h> #import <Photos/Photos.h> @interface CustomAlbum : NSObject //Creating album with given name +(void)makeAlbumWithTitle:(NSString *)title onSuccess:(void(^)(NSString *AlbumId))onSuccess onError: (void(^)(NSError * error)) onError; //Get the album by name +(PHAssetCollection *)getMyAlbumWithName:(NSString*)AlbumName; //Add a image +(void)addNewAssetWithImage:(UIImage *)image toAlbum:(PHAssetCollection *)album onSuccess:(void(^)(NSString *ImageId))onSuccess onError: (void(^)(NSError * error)) onError; //get the image using identifier + (void)getImageWithIdentifier:(NSString*)imageId onSuccess:(void(^)(UIImage *image))onSuccess onError: (void(^)(NSError * error)) onError; @end // CustomAlbum.m
#import "CustomAlbum.h" @implementation CustomAlbum #pragma mark - PHPhoto +(void)makeAlbumWithTitle:(NSString *)title onSuccess:(void(^)(NSString *AlbumId))onSuccess onError: (void(^)(NSError * error)) onError { //Check weather the album already exist or not if (![self getMyAlbumWithName:title]) { [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{ // Request editing the album. PHAssetCollectionChangeRequest *createAlbumRequest = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:title]; // Get a placeholder for the new asset and add it to the album editing request. PHObjectPlaceholder * placeHolder = [createAlbumRequest placeholderForCreatedAssetCollection]; if (placeHolder) { onSuccess(placeHolder.localIdentifier); } } completionHandler:^(BOOL success, NSError *error) { NSLog(@"Finished adding asset. %@", (success ? @"Success" : error)); if (error) { onError(error); } }]; } } +(void)addNewAssetWithImage:(UIImage *)image toAlbum:(PHAssetCollection *)album onSuccess:(void(^)(NSString *ImageId))onSuccess onError: (void(^)(NSError * error)) onError { [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{ // Request creating an asset from the image. PHAssetChangeRequest *createAssetRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:image]; // Request editing the album. PHAssetCollectionChangeRequest *albumChangeRequest = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:album]; // Get a placeholder for the new asset and add it to the album editing request. PHObjectPlaceholder * placeHolder = [createAssetRequest placeholderForCreatedAsset]; [albumChangeRequest addAssets:@[ placeHolder ]]; NSLog(@"%@",placeHolder.localIdentifier); if (placeHolder) { onSuccess(placeHolder.localIdentifier); } } completionHandler:^(BOOL success, NSError *error) { NSLog(@"Finished adding asset. %@", (success ? @"Success" : error)); if (error) { onError(error); } }]; } +(PHAssetCollection *)getMyAlbumWithName:(NSString*)AlbumName { #if 0 NSString * identifier = [[NSUserDefaults standardUserDefaults]objectForKey:kAlbumIdentifier]; if (!identifier) return nil; PHFetchResult *assetCollections = [PHAssetCollection fetchAssetCollectionsWithLocalIdentifiers:@[identifier] options:nil]; #else PHFetchResult *assetCollections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil]; #endif NSLog(@"assetCollections.count = %lu", assetCollections.count); if (assetCollections.count == 0) return nil; __block PHAssetCollection * myAlbum; [assetCollections enumerateObjectsUsingBlock:^(PHAssetCollection *album, NSUInteger idx, BOOL *stop) { NSLog(@"album:%@", album); NSLog(@"album.localizedTitle:%@", album.localizedTitle); if ([album.localizedTitle isEqualToString:AlbumName]) { myAlbum = album; *stop = YES; } }]; if (!myAlbum) return nil; return myAlbum; } +(NSArray *)getAssets:(PHFetchResult *)fetch { __block NSMutableArray * assetArray = NSMutableArray.new; [fetch enumerateObjectsUsingBlock:^(PHAsset *asset, NSUInteger idx, BOOL *stop) { NSLog(@"asset:%@", asset); [assetArray addObject:asset]; }]; return assetArray; } + (void)getImageWithIdentifier:(NSString*)imageId onSuccess:(void(^)(UIImage *image))onSuccess onError: (void(^)(NSError * error)) onError { NSError *error = [[NSError alloc] init]; PHFetchResult *assets = [PHAsset fetchAssetsWithLocalIdentifiers:@[imageId] options:nil]; if (assets.count == 0) onError(error); NSArray * assetArray = [self getAssets:assets]; PHImageManager *manager = [PHImageManager defaultManager]; CGRect screenRect = [[UIScreen mainScreen] bounds]; [manager requestImageForAsset:assetArray.firstObject targetSize:screenRect.size contentMode:PHImageContentModeAspectFit options:nil resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) { onSuccess(result); }]; } @end
然后使用这种方法拍摄button点击创build自定义相册，并保存在该自定义相册的图像。
// Take Image Button Method - (void)snapButtonPressed:(UIButton *)button { [self.camera capture:^(LLSimpleCamera *camera, UIImage *image, NSDictionary *metadata, NSError *error) { if(!error) { NSString * info = [NSString stringWithFormat:@"Size: %@ - Orientation: %ld", NSStringFromCGSize(image.size), (long)image.imageOrientation]; [CustomAlbum addNewAssetWithImage:image toAlbum:[CustomAlbum getMyAlbumWithName:CSAlbum] onSuccess:^(NSString *ImageId) { NSLog(@"%@",ImageId); recentImg = ImageId; } onError:^(NSError *error) { NSLog(@"probelm in saving image"); }]; } else { NSLog(@"An error has occured: %@", error); } } exactSeenImage:YES]; }
这是有用的代码。
__block PHAssetCollection *collection; // Find the album PHFetchOptions *fetchOptions = [[PHFetchOptions alloc] init]; fetchOptions.predicate = [NSPredicate predicateWithFormat:@"title = %@", @"YOUR_CUSTOM_ALBUM_NAME"]; collection = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAny options:fetchOptions].firstObject; PHFetchResult *collectionResult = [PHAsset fetchAssetsInAssetCollection:collection options:nil]; [collectionResult enumerateObjectsUsingBlock:^(PHAsset *asset, NSUInteger idx, BOOL *stop) { //add assets to an array for later use in the uicollectionviewcell }];
只要尝试一次这个代码..你可以使用这个代码在一个数组中的所有图像： –
-(void)getAllPictures { __block PHAssetCollection *collection; // Find the album PHFetchOptions *fetchOptions = [[PHFetchOptions alloc] init]; fetchOptions.predicate = [NSPredicate predicateWithFormat:@"title = %@", @"YOUR_CUSTOM_ALBUM_NAME"]; collection = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAny options:fetchOptions].firstObject; PHFetchResult *collectionResult = [PHAsset fetchAssetsInAssetCollection:collection options:nil]; NSMutableArray *assets = [[NSMutableArray alloc] init]; [collectionResult enumerateObjectsUsingBlock:^(PHAsset *asset, NSUInteger idx, BOOL *stop) { [assets addObject:asset]; }]; PHImageRequestOptions * requestOptions = [[PHImageRequestOptions alloc] init]; //requestOptions.resizeMode = PHImageRequestOptionsResizeModeExact; //requestOptions.deliveryMode = PHImageRequestOptionsDeliveryModeHighQualityFormat; // this one is key //requestOptions.synchronous = true; PHImageManager *manager = [PHImageManager defaultManager]; NSMutableArray *images = [NSMutableArray arrayWithCapacity:[assets count]]; // assets contains PHAsset objects. __block UIImage *ima; for (PHAsset *asset in assets) { // Do something with the asset [manager requestImageForAsset:asset targetSize:PHImageManagerMaximumSize//CGSizeMake(300, 300) contentMode:PHImageContentModeDefault options:requestOptions resultHandler:^void(UIImage *image, NSDictionary *info) { ima = image; [images addObject:ima]; }]; } NSLog(@"images %@", images); //You will get all images into this images array. }
有关更多详情，请参阅使用照片框架的示例应用程序 。
希望，这是你要找的。 任何关心回到我身边。 🙂