访问库中的Burst Mode照片

Question

我正在尝试访问用户使用突发模式拍摄的iOS资源库中的照片.我正在尝试使用ALAssetsLibrary和过滤照片:

- (void)findBurstModePhotos
{
    ALAssetsFilter *allPhotos = [ALAssetsFilter allPhotos];

    ALAssetsLibrary *assetLibrary = [[ALAssetsLibrary alloc] init];

    [assetLibrary enumerateGroupsWithTypes:ALAssetsGroupAll
                                usingBlock:^(ALAssetsGroup *group,
                                             BOOL *stop) {
                                    [group setAssetsFilter:allPhotos];

                                    NSLog(@"Group: %@",
                                          [group valueForProperty:
                                           ALAssetsGroupPropertyName]);

                                    if ([group numberOfAssets] > 0) {
                                        [self evaluateGroup:group];
                                    }
                                }
                              failureBlock:^(NSError *error) {
                                  NSLog(@"Failure enumerating groups: %@",
                                        [error localizedDescription]);
                              }];
}

- (void)evaluateGroup:(ALAssetsGroup *)group
{
    [group enumerateAssetsUsingBlock:^(ALAsset *result,
                                       NSUInteger index,
                                       BOOL *stop) {
        NSLog(@"Photo date: %@", [result valueForProperty:ALAssetPropertyDate]);
    }];
}

不幸的是,这会将Burst Mode照片作为单张照片返回.是否有支持的方式单独获取Burst Mode照片？我想从单个突发模式会话中获取每张照片.

Answer 1

根据我的理解，连拍模式照片将被一张一张地添加到库中。ALAssetProperty每张图像的类型将为ALAssetTypePhoto。因此您可以使用下面的 ALAsset 块分别获取每张照片。您无法一次仅检索一组连拍模式照片，因为只有 7 种类型ALAssetsGroupTypes和 3 种ALAssetsFilters可用。他们都没有处理连拍模式照片。

我希望苹果将来能够提供连拍照片过滤功能。

---------------------------- ALAssetsGroupType -------------------------------------------

ALAssetsGroupLibrary      // The Library group that includes all assets.
ALAssetsGroupAlbum        // All the albums synced from iTunes or created on the device.
ALAssetsGroupEvent        // All the events synced from iTunes.
ALAssetsGroupFaces        // All the faces albums synced from iTunes.
ALAssetsGroupSavedPhotos  // The Saved Photos album.
ALAssetsGroupPhotoStream  // The PhotoStream album.
ALAssetsGroupAll          // The same as ORing together all the available group types,with the exception that ALAssetsGroupLibrary is not included.


-------------------------- ALAssetsFilter ------------------------------------------------

+ (ALAssetsFilter *)allPhotos; // Get all photos assets in the assets group.
+ (ALAssetsFilter *)allVideos; // Get all video assets in the assets group.
+ (ALAssetsFilter *)allAssets; // Get all assets in the group.

使用下面的代码分别获取每张照片，包括连拍模式照片，

- (void)findBurstModePhotos
{
    ALAssetsLibrary *assetLibrary = [ViewController defaultAssetsLibrary];

    [assetLibrary enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:^(ALAssetsGroup *group, BOOL *stop)
    {
    [group enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {

      if(result)
      {
        [self evaluateGroup:group];
      }

    }];

    } failureBlock:^(NSError *error) {
        NSLog(@"Error loading images %@", error);
    }];
}

- (void)evaluateGroup:(ALAssetsGroup *)group
{
    [group enumerateAssetsUsingBlock:^(ALAsset *result,
                                       NSUInteger index,
                                       BOOL *stop) {
        NSLog(@"Photo date: %@", [result valueForProperty:ALAssetPropertyDate]);
    }];
}

+ (ALAssetsLibrary *)defaultAssetsLibrary
{
    static dispatch_once_t pred = 0;
    static ALAssetsLibrary *library = nil;
    dispatch_once(&pred, ^{
        library = [[ALAssetsLibrary alloc] init];
    });
    return library;
}

输出日志：

Photo date: 2013-05-06 15:57:21 +0000 //non burst image.
Photo date: 2013-05-06 15:57:41 +0000 //non burst image.
Photo date: 2013-12-20 21:10:40 +0000 //burst image.
Photo date: 2013-12-20 21:10:41 +0000 //burst image.
Photo date: 2013-12-20 21:10:41 +0000 //burst image.
Photo date: 2013-12-20 21:10:41 +0000 //burst image.
Photo date: 2013-12-20 21:10:41 +0000 //burst image.
Photo date: 2013-12-20 21:10:42 +0000 //burst image.
Photo date: 2013-12-20 21:10:42 +0000 //burst image.
Photo date: 2013-12-20 21:10:42 +0000 //burst image.
Photo date: 2013-12-20 21:10:43 +0000 //burst image.
Photo date: 2013-12-20 21:10:43 +0000 //burst image.
Photo date: 2013-12-20 21:10:43 +0000 //burst image.
Photo date: 2013-12-20 21:10:44 +0000 //burst image.
Photo date: 2013-12-20 21:10:44 +0000 //burst image.
Photo date: 2013-12-20 21:10:44 +0000 //burst image.
Photo date: 2013-12-20 21:10:44 +0000 //burst image.
Photo date: 2013-12-20 21:10:45 +0000 //burst image.
Photo date: 2013-12-20 21:10:45 +0000 //burst image.
Photo date: 2013-12-20 21:10:45 +0000 //burst image.
Photo date: 2013-12-20 21:10:45 +0000 //burst image.
Photo date: 2013-12-20 21:10:46 +0000 //burst image.

笔记：

如果连拍模式照片捕获相机是您的应用程序的一部分，则将ALAsset URL's捕获的照片保存到照片库时存储。您可以使用ALAsset URL's通过ALAsset库保存的内容检索此照片。