使用 Adam 的回答和 Marin Todorov 的 ALAssetsLibrary 上的类别，ALAssetsLibrary+CustomPhotoAlbum 创建相册，并将照片放入其中，下面的代码替换了该类别中的主要 workHorse，它适用于 iOS7 设备和 iOS 8.1 设备，供需要的人使用两者兼得。
它在未知类上给出了两个关于 performSelector 的警告，任何改进都值得赞赏：
（它不会从您没有创建的共享相册中复制照片，并且会失败并显示消息，那里的任何增强功能也会很好）
1）添加“照片”框架，设置为“可选”
2) 包括导入行#import <Photos/PHPhotoLibrary.h>
//----------------------------------------------------------------------------------------
- (void)addAssetURL:(NSURL *)assetURL
toAlbum:(NSString *)albumName
completion:(ALAssetsLibraryWriteImageCompletionBlock)completion
failure:(ALAssetsLibraryAccessFailureBlock)failure
{
NSLog();
__block BOOL albumWasFound = NO;
//-----------------------------------------
ALAssetsLibraryGroupsEnumerationResultsBlock enumerationBlock;
enumerationBlock = ^(ALAssetsGroup *group, BOOL *stop)
{
NSLog(@" ALAssetsLibraryGroupsEnumerationResultsBlock");
// Compare the names of the albums
if ([albumName compare:[group valueForProperty:ALAssetsGroupPropertyName]] == NSOrderedSame)
{
NSLog(@"--------------Target album is found");
// Target album is found
albumWasFound = YES;
// Get a hold of the photo's asset instance
// If the user denies access to the application, or if no application is allowed to
// access the data, the failure block is called.
ALAssetsLibraryAssetForURLResultBlock assetForURLResultBlock =
[self _assetForURLResultBlockWithGroup:group
assetURL:assetURL
completion:completion
failure:failure];
[self assetForURL:assetURL
resultBlock:assetForURLResultBlock
failureBlock:failure];
// Album was found, bail out of the method
*stop = YES;
}
if (group == nil && albumWasFound == NO)
{
NSLog(@"--------------Target album does not exist");
// Photo albums are over, target album does not exist, thus create it
// Since you use the assets library inside the block,
// ARC will complain on compile time that there’s a retain cycle.
// When you have this – you just make a weak copy of your object.
ALAssetsLibrary * __weak weakSelf = self;
// If iOS version is lower than 5.0, throw a warning message
if (! [self respondsToSelector:@selector(addAssetsGroupAlbumWithName:resultBlock:failureBlock:)])
{
NSLog(@"--------------Target album does not exist and does not respond to addAssetsGroupAlbumWithName");
} else {
NSLog(@"--------------Target album does not exist addAssetsGroupAlbumWithName");
// ----------- PHPhotoLibrary_class will only be non-nil on iOS 8.x.x -----------
Class PHPhotoLibrary_class = NSClassFromString(@"PHPhotoLibrary");
NSLog(@"PHPhotoLibrary_class %@ ", PHPhotoLibrary_class);
if (PHPhotoLibrary_class)
{
NSLog(@"iOS8");
// --------- dynamic runtime code -----------
id sharedPhotoLibrary = [PHPhotoLibrary_class performSelector:NSSelectorFromString(@"sharedPhotoLibrary")];
NSLog(@"sharedPhotoLibrary %@ ", sharedPhotoLibrary);
SEL performChanges = NSSelectorFromString(@"performChanges:completionHandler:");
NSMethodSignature *methodSig = [sharedPhotoLibrary methodSignatureForSelector:performChanges];
NSInvocation* inv = [NSInvocation invocationWithMethodSignature:methodSig];
[inv setTarget:sharedPhotoLibrary];
[inv setSelector:performChanges];
void(^firstBlock)() = ^void()
{
NSLog(@"firstBlock");
Class PHAssetCollectionChangeRequest_class = NSClassFromString(@"PHAssetCollectionChangeRequest");
SEL creationRequestForAssetCollectionWithTitle = NSSelectorFromString(@"creationRequestForAssetCollectionWithTitle:");
NSLog(@"PHAssetCollectionChangeRequest_class %@ ", PHAssetCollectionChangeRequest_class);
[PHAssetCollectionChangeRequest_class performSelector:creationRequestForAssetCollectionWithTitle withObject:albumName];
};
void (^secondBlock)(BOOL success, NSError *error) = ^void(BOOL success, NSError *error)
{
NSLog(@"secondBlock");
if (success)
{
NSLog(@"success");
[self enumerateGroupsWithTypes:ALAssetsGroupAlbum usingBlock:^(ALAssetsGroup *group, BOOL *fullStop)
{
if (group)
{
NSLog(@"group %@ ", group);
NSString *name = [group valueForProperty:ALAssetsGroupPropertyName];
if ([albumName isEqualToString:name])
{
NSLog(@"[albumName isEqualToString:name] %@ ", name);
ALAssetsLibraryAssetForURLResultBlock assetForURLResultBlock =
[self _assetForURLResultBlockWithGroup:group
assetURL:assetURL
completion:completion
failure:failure];
[self assetForURL:assetURL
resultBlock:assetForURLResultBlock
failureBlock:failure];
*fullStop = YES;
}
}
} failureBlock:failure];
}
if (error)
{
NSLog(@"Error creating album: %@", error);
}
};
// Set the success and failure blocks.
[inv setArgument:&firstBlock atIndex:2];
[inv setArgument:&secondBlock atIndex:3];
[inv invoke];
} else {
NSLog(@"iOS7");
[self addAssetsGroupAlbumWithName:albumName resultBlock:^(ALAssetsGroup *createdGroup)
{
// Get the photo's instance, add the photo to the newly created album
ALAssetsLibraryAssetForURLResultBlock assetForURLResultBlock =
[weakSelf _assetForURLResultBlockWithGroup:createdGroup
assetURL:assetURL
completion:completion
failure:failure];
[weakSelf assetForURL:assetURL
resultBlock:assetForURLResultBlock
failureBlock:failure];
}
failureBlock:failure];
}
}
// Should be the last iteration anyway, but just in case
*stop = YES;
}
};
// Search all photo albums in the library
[self enumerateGroupsWithTypes:ALAssetsGroupAlbum
usingBlock:enumerationBlock
failureBlock:failure];
}