/** * 保存圖片到相冊 */- (IBAction)saveImage {  PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];  if (status == PHAuthorizationStatusDenied) {    NSLog(@"請到【設置-隱私-照片】打開訪問開關");  } else if (status == PHAuthorizationStatusRestricted) {    NSLog(@"無法訪問相冊");  } else {    // 保存相片的標識    __block NSString *assetId = nil;           [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{      // 保存相片到相機膠卷，并返回標識      assetId = [PHAssetCreationRequest creationRequestForAssetFromImage:[UIImage imageNamed:@"logo"]].placeholderForCreatedAsset.localIdentifier;    } completionHandler:^(BOOL success, NSError * _Nullable error) {      if (!success) {        NSLog(@"保存失敗：%@", error);        return;      }               // 根據標識獲得相片對象      PHAsset *asset = [PHAsset fetchAssetsWithLocalIdentifiers:@[assetId] options:nil].lastObject;               // 拿到自定義的相冊對象      PHAssetCollection *collection = [self collection];      if (collection == nil) return;               // 保存相片到自定義相冊中      [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{        [[PHAssetCollectionChangeRequest changeRequestForAssetCollection:collection] addAssets:@[asset]];      } completionHandler:^(BOOL success, NSError * _Nullable error) {        if (success) {          NSLog(@"保存成功");        } else {          NSLog(@"保存失敗：%@", error);        }      }];    }];  }}

/** * 查詢所有的圖片 */- (IBAction)searchAllImages {       // 遍歷所有的自定義相冊  PHFetchResult<PHAssetCollection *> *collectionResult0 = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];  for (PHAssetCollection *collection in collectionResult0) {    [self searchAllImagesInCollection:collection];  }       // 獲得相機膠卷的圖片  PHFetchResult<PHAssetCollection *> *collectionResult1 = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];  for (PHAssetCollection *collection in collectionResult1) {    if (![collection.localizedTitle isEqualToString:@"Camera Roll"]) continue;    [self searchAllImagesInCollection:collection];    break;  }}   /** * 查詢某個相冊里面的所有圖片 */- (void)searchAllImagesInCollection:(PHAssetCollection *)collection{  // 采取同步獲取圖片（只獲得一次圖片）  PHImageRequestOptions *imageOptions = [[PHImageRequestOptions alloc] init];  imageOptions.synchronous = YES;       NSLog(@"相冊名字：%@", collection.localizedTitle);       // 遍歷這個相冊中的所有圖片  PHFetchResult<PHAsset *> *assetResult = [PHAsset fetchAssetsInAssetCollection:collection options:nil];  for (PHAsset *asset in assetResult) {    // 過濾非圖片    if (asset.mediaType != PHAssetMediaTypeImage) continue;           // 圖片原尺寸    CGSize targetSize = CGSizeMake(asset.pixelWidth, asset.pixelHeight);    // 請求圖片    [[PHImageManager defaultManager] requestImageForAsset:asset targetSize:targetSize contentMode:PHImageContentModeDefault options:imageOptions resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {      NSLog(@"圖片：%@", result);    }];  }}