iOS图片保存与搜索功能的代码实现

/** * 保存图片到相册 */- (IBAction)saveImage {  PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus];  if (status == PHAuthorizationStatusDenied) {    NSLog(@"请到【设置-隐私-照片】打开访问开关");  } else if (status == PHAuthorizationStatusRestricted) {    NSLog(@"无法访问相册");  } else {    // 保存相片的标识    __block NSString *assetId = nil;           [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{      // 保存相片到相机胶卷，并返回标识      assetId = [PHAssetCreationRequest creationRequestForAssetFromImage:[UIImage imageNamed:@"logo"]].placeholderForCreatedAsset.localIdentifier;    } completionHandler:^(BOOL success, NSError * _Nullable error) {      if (!success) {        NSLog(@"保存失败：%@", error);        return;      }               // 根据标识获得相片对象      PHAsset *asset = [PHAsset fetchAssetsWithLocalIdentifiers:@[assetId] options:nil].lastObject;               // 拿到自定义的相册对象      PHAssetCollection *collection = [self collection];      if (collection == nil) return;               // 保存相片到自定义相册中      [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{        [[PHAssetCollectionChangeRequest changeRequestForAssetCollection:collection] addAssets:@[asset]];      } completionHandler:^(BOOL success, NSError * _Nullable error) {        if (success) {          NSLog(@"保存成功");        } else {          NSLog(@"保存失败：%@", error);        }      }];    }];  }}

/** * 查询所有的图片 */- (IBAction)searchAllImages {       // 遍历所有的自定义相册  PHFetchResult *collectionResult0 = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];  for (PHAssetCollection *collection in collectionResult0) {    [self searchAllImagesInCollection:collection];  }       // 获得相机胶卷的图片  PHFetchResult *collectionResult1 = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];  for (PHAssetCollection *collection in collectionResult1) {    if (![collection.localizedTitle isEqualToString:@"Camera Roll"]) continue;    [self searchAllImagesInCollection:collection];    break;  }}   /** * 查询某个相册里面的所有图片 */- (void)searchAllImagesInCollection:(PHAssetCollection *)collection{  // 采取同步获取图片（只获得一次图片）  PHImageRequestOptions *imageOptions = [[PHImageRequestOptions alloc] init];  imageOptions.synchronous = YES;       NSLog(@"相册名字：%@", collection.localizedTitle);       // 遍历这个相册中的所有图片  PHFetchResult *assetResult = [PHAsset fetchAssetsInAssetCollection:collection options:nil];  for (PHAsset *asset in assetResult) {    // 过滤非图片    if (asset.mediaType != PHAssetMediaTypeImage) continue;           // 图片原尺寸    CGSize targetSize = CGSizeMake(asset.pixelWidth, asset.pixelHeight);    // 请求图片    [[PHImageManager defaultManager] requestImageForAsset:asset targetSize:targetSize contentMode:PHImageContentModeDefault options:imageOptions resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {      NSLog(@"图片：%@", result);    }];  }}