PHAssetCollection *collection = (PHAssetCollection *)result;
PHFetchOptions*options = [[PHFetchOptionsalloc]init];
options.predicate = [NSPredicate predicateWithFormat:@"mediaType = %d OR mediaType = %d",PHAssetMediaTypeImage, PHAssetMediaTypeVideo];
?NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:NO];
//ascending為NO，即為逆序(由現(xiàn)在到過去)， ascending為YES時即為默認排序，由遠到近
?options.sortDescriptors=@[sort];
?PHFetchResult*assetsFetchResult =[PHAssetfetchAssetsInAssetCollection:collectionoptions:options];
