iOS8.0 使用Photos.framework对相册的常用操作

自己最近抽空写了一个相册多选框架，用到对一些对相册相关的操作，使用的便是iOS8.0之后，apple推出的新框架 Photos.framework

github地址：https://github.com/longitachi/ZLPhotoBrowser 喜欢的朋友可以给个star

下载的朋友建议去git上下载，由于csdn的资源不支持实施更改，git上将持续更新

废话不多说，来干货

以下操作都需要导入<Photos/Photos.h>头文件

1.判断相册访问权限

首先我们访问相册，肯定有需要判断是否有访问权限的时候，然后做出相应的操作

PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];
if (status == PHAuthorizationStatusRestricted ||status == PHAuthorizationStatusDenied) {// 这里便是无访问权限
}

2.实时监听相册内部图片变化

[[PHPhotoLibrary sharedPhotoLibrary] registerChangeObserver:self];

当然，这个"self"是要遵守 PHPhotoLibraryChangeObserver 协议的

回调方法如下，不过这个地方是有一个坑的，就是这个回调是在一个子线程里面，如果你想要对UI进行操作的话，则必须回调主线程

//相册变化回调
- (void)photoLibraryDidChange:(PHChange *)changeInstance
{dispatch_sync(dispatch_get_main_queue(), ^{// your codes});
}

3.读取相册内所有图片资源

对相册资源的相关操作，apple多都放在了 PHAsset内

#pragma mark - 获取相册内所有照片资源
- (NSArray<PHAsset *> *)getAllAssetInPhotoAblumWithAscending:(BOOL)ascending
{NSMutableArray<PHAsset *> *assets = [NSMutableArray array];PHFetchOptions *option = [[PHFetchOptions alloc] init];//ascending 为YES时，按照照片的创建时间升序排列;为NO时，则降序排列option.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:ascending]];PHFetchResult *result = [PHAsset fetchAssetsWithMediaType:PHAssetMediaTypeImage options:option];[result enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {PHAsset *asset = (PHAsset *)obj;NSLog(@"照片名%@", [asset valueForKey:@"filename"]);[assets addObject:asset];}];return assets;
}

4.根据获取的PHAsset对象，解析图片

PHImageRequestOptions *option = [[PHImageRequestOptions alloc] init];//仅显示缩略图，不控制质量显示/**PHImageRequestOptionsResizeModeNone,PHImageRequestOptionsResizeModeFast, //根据传入的size，迅速加载大小相匹配(略大于或略小于)的图像PHImageRequestOptionsResizeModeExact //精确的加载与传入size相匹配的图像*/option.resizeMode = PHImageRequestOptionsResizeModeFast;option.networkAccessAllowed = YES;//param：targetSize 即你想要的图片尺寸，若想要原尺寸则可输入PHImageManagerMaximumSize[[PHCachingImageManager defaultManager] requestImageForAsset:asset targetSize:size contentMode:PHImageContentModeAspectFit options:option resultHandler:^(UIImage * _Nullable image, NSDictionary * _Nullable info) {//解析出来的图片}];

5.获取所有智能相册（即默认的，如“所有照片”“屏幕快照”等）

PHFetchResult *smartAlbums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
[smartAlbums enumerateObjectsUsingBlock:^(PHAssetCollection * _Nonnull collection, NSUInteger idx, BOOL *stop) {NSLog(@"相册名字:%@", collection.localizedTitle);
}];

智能相册的title不出意外都是英文，下面提供一个对应的中文名

- (NSString *)transformAblumTitle:(NSString *)title
{if ([title isEqualToString:@"Slo-mo"]) {return @"慢动作";} else if ([title isEqualToString:@"Recently Added"]) {return @"最近添加";} else if ([title isEqualToString:@"Favorites"]) {return @"最爱";} else if ([title isEqualToString:@"Recently Deleted"]) {return @"最近删除";} else if ([title isEqualToString:@"Videos"]) {return @"视频";} else if ([title isEqualToString:@"All Photos"]) {return @"所有照片";} else if ([title isEqualToString:@"Selfies"]) {return @"自拍";} else if ([title isEqualToString:@"Screenshots"]) {return @"屏幕快照";} else if ([title isEqualToString:@"Camera Roll"]) {return @"相机胶卷";}return nil;
}

在项目plist配置文件中添加如下键，值设为YES，即可自动匹配手机系统语言，返回相册名字。不需要进行上列判断

Localized resources can be mixed YES
//或者右键plist文件Open As->Source Code 添加
<key>CFBundleAllowMixedLocalizations</key>
<true/>

6.获取所有用户创建的相册

PHFetchResult *userAlbums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeSmartAlbumUserLibrary options:nil];
[userAlbums enumerateObjectsUsingBlock:^(PHAssetCollection * _Nonnull collection, NSUInteger idx, BOOL * _Nonnull stop) {NSLog(@"相册名字:%@", collection.localizedTitle);
}];

7.获取每个相册下的所有照片对象(PHAsset)

#pragma mark - 获取指定相册内的所有图片
- (NSArray<PHAsset *> *)getAssetsInAssetCollection:(PHAssetCollection *)assetCollection ascending:(BOOL)ascending
{NSMutableArray<PHAsset *> *arr = [NSMutableArray array];PHFetchResult *result = [self fetchAssetsInAssetCollection:assetCollection ascending:ascending];[result enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {[arr addObject:obj];//这个obj即PHAsset对象}];return arr;
}

8.验证该图片是否在本地（若开启了iCloud照片存储，则图片会定时上传到网上，本地不存在）

PHImageRequestOptions *option = [[PHImageRequestOptions alloc] init];option.networkAccessAllowed = NO;option.synchronous = YES;__block BOOL isInLocalAblum = YES;[[PHCachingImageManager defaultManager] requestImageDataForAsset:asset options:option resultHandler:^(NSData * _Nullable imageData, NSString * _Nullable dataUTI, UIImageOrientation orientation, NSDictionary * _Nullable info) {isInLocalAblum = imageData ? YES : NO;}];return isInLocalAblum;

9.获取LivePhoto

PHLivePhotoRequestOptions *option = [[PHLivePhotoRequestOptions alloc] init];option.version = PHImageRequestOptionsVersionCurrent;option.deliveryMode = PHImageRequestOptionsDeliveryModeOpportunistic;option.networkAccessAllowed = YES;[[PHCachingImageManager defaultManager] requestLivePhotoForAsset:asset targetSize:PHImageManagerMaximumSize contentMode:PHImageContentModeAspectFit options:option resultHandler:^(PHLivePhoto * _Nullable livePhoto, NSDictionary * _Nullable info) {if (completion) completion(livePhoto, info);}];

播放LivePhoto则需要借助系统框架 PhotosUI.framework，我们直接把上边block中请求的PHLivePhoto类型对象赋值给 PHLivePhotoView 类的UI即可，调用 startPlaybackWithStyle: 方法即可进行播放

10.获取Video

[[PHCachingImageManager defaultManager] requestPlayerItemForVideo:asset options:nil resultHandler:^(AVPlayerItem * _Nullable playerItem, NSDictionary * _Nullable info) {if (completion) completion(playerItem, info);}];

播放视频则需要使用 AVPlayerLayer，使用对应方法播放即可