我相信我已经用以下代码解决了这个问题:
NSPredicate *testForPanoramasPredicate = [NSPredicate predicateWithFormat:@"(mediaSubtypes & %i) == %i",PHAssetMediaSubtypePhotoPanorama,PHAssetMediaSubtypePhotoPanorama]
NSArray *testForAllPanoramas = [testForAllPhotos filteredArrayUsingPredicate:testForPanoramasPredicate]
也许更好的方法是,如果您不想进行初始图像谓词:
NSPredicate *testForPanoramasPredicate = [NSPredicate predicateWithFormat:
@"(mediaType == %i && (mediaSubtypes & %i) == %i))",
PHAssetMediaTypeImage,PHAssetMediaSubtypePhotoPanorama,PHAssetMediaSubtypePhotoPanorama]
以下是完整代码,适用于想要检查相册是否包含特定媒体子类型的用户;这对于在相册上显示UI徽章非常有用。
PHFetchResult *assetsInCollection = [PHAsset fetchAssetsInAssetCollection:sub options:fetchOptions];
if (assetsInCollection.count > 0)
{
NSArray *allAssets = [assetsInCollection objectsAtIndexes:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(0, assetsInCollection.count)]];
NSPredicate *testForPanoramasPredicate = [NSPredicate predicateWithFormat:@"(mediaType == %i && (mediaSubtypes & %i) == %i))",PHAssetMediaTypeImage,PHAssetMediaSubtypePhotoPanorama,PHAssetMediaSubtypePhotoPanorama];
NSPredicate *testForHDRPredicate = [NSPredicate predicateWithFormat:@"(mediaType == %i && (mediaSubtypes & %i) == %i))",PHAssetMediaTypeImage,PHAssetMediaSubtypePhotoHDR,PHAssetMediaSubtypePhotoHDR];
NSPredicate *testForVideosPredicate = [NSPredicate predicateWithFormat:@"mediaType = %i",PHAssetMediaTypeVideo];
NSPredicate *testForSlomoPredicate = [NSPredicate predicateWithFormat:@"(mediaType == %i && (mediaSubtypes & %i) == %i))",PHAssetMediaTypeVideo,PHAssetMediaSubtypeVideoHighFrameRate,PHAssetMediaSubtypeVideoHighFrameRate];
NSPredicate *testForTimelapsePredicate = [NSPredicate predicateWithFormat:@"(mediaType == %i && (mediaSubtypes & %i) == %i))",PHAssetMediaTypeVideo,PHAssetMediaSubtypeVideoTimelapse,PHAssetMediaSubtypeVideoTimelapse];
NSPredicate *testForStreamedPredicate = [NSPredicate predicateWithFormat:@"(mediaType == %i && (mediaSubtypes & %i) == %i))",PHAssetMediaTypeVideo,PHAssetMediaSubtypeVideoStreamed,PHAssetMediaSubtypeVideoStreamed];
NSArray *testForAllPanoramas = [allAssets filteredArrayUsingPredicate:testForPanoramasPredicate];
NSArray *testForAllHDR = [allAssets filteredArrayUsingPredicate:testForHDRPredicate];
NSArray *testForAllVideos = [allAssets filteredArrayUsingPredicate:testForVideosPredicate];
NSArray *testForAllSlomo = [allAssets filteredArrayUsingPredicate:testForSlomoPredicate];
NSArray *testForAllTimelapse = [allAssets filteredArrayUsingPredicate:testForTimelapsePredicate];
NSArray *testForAllStreamed = [allAssets filteredArrayUsingPredicate:testForStreamedPredicate];
NSArray *allPossibilitiesArray = @[testForAllPanoramas,testForAllHDR,testForAllVideos,testForAllSlomo,testForAllTimelapse,testForAllStreamed];
for (NSArray *sub in allPossibilitiesArray)
{
if (sub.count == allAssets.count)
{
PHAsset *firstAsset = sub.firstObject;
[dataSource setObject:[NSNumber numberWithInt:firstAsset.mediaSubtypes] forKey:@"MediaSubtype"];
}
}
}
(mediaSubtypes & %i)
周围加上()
,因为&
的优先级低于==
,所以它最终会评估(mediaSubtypes & (%i == %i))
。 - dan