错误：“不支持的谓词提取选项：mediaType的== 2”

Question

我试图用smartAlbum产生的或者仅视频或仅照片或两者的一个阵列。 你可以看到我的代码如下：

    PHFetchResult *collectionList = [PHCollectionList fetchMomentListsWithSubtype:PHCollectionListSubtypeMomentListCluster options:nil];
    PHFetchOptions *options = nil;
        if (self.xSelected) {
            options = [[PHFetchOptions alloc] init];
            options.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:NO]];
            options.predicate = [NSPredicate predicateWithFormat:@"mediaType = %d",PHAssetMediaTypeImage];
        }
        if (self.ySelected) {
            options = [[PHFetchOptions alloc] init];
            options.predicate = [NSPredicate predicateWithFormat:@"mediaType = %d",PHAssetMediaTypeVideo];
        }

    [collectionList enumerateObjectsUsingBlock:^(PHCollectionList *collection, NSUInteger idx, BOOL *stop) {
        PHFetchResult *momentsInCollection = [PHAssetCollection fetchMomentsInMomentList:collection options:options];
        for (id moment in momentsInCollection) {
            PHAssetCollection *castedMoment = (PHAssetCollection *)moment;
            [_smartAlbums insertObject:castedMoment atIndex:0];
        }
    }];

然而，这是不断突破的block内的第一行，并给予下列错误：Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Unsupported predicate in fetch options: mediaType == 2'

我做了一些研究，发现这link。 我还是想知道，这是一个苹果的错误，如果它只是一些错我的代码。 这似乎是它的工作对于提到这个answer，这太奇怪了怎么把它基本上是同样的事情的人。

提前致谢， 阿尼什

编辑： 我想我发现苹果的文档答案here。貌似mediaType的是仅适用于PHAsset而不是PHAssetCollection的关键。所以现在我想的问题是如何获得PFAssetCollection仅视频或仅适用于图像。

Answer 1

使用此方法可分别获得照片和视频资产阵列。

获取所有视频

func getAllVideos(completion:@escaping  (_ videoAssets : [PHAsset]?) -> Void) {
    var videoAssets : [PHAsset] = []

    let fetchOptions = PHFetchOptions()
    fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate",ascending: false)]
    fetchOptions.predicate = NSPredicate(format: "mediaType = %d", PHAssetMediaType.video.rawValue)
    let allVideo = PHAsset.fetchAssets(with: .video, options: fetchOptions)
    allVideo.enumerateObjects { (asset, index, bool) in
        videoAssets.append(asset)
    }
    completion(videoAssets)
}

获取所有图片

func getAllPhotos(completion:@escaping  (_ photosAssets : [PHAsset]?) -> Void) {
    var photosAssets : [PHAsset] = []

    let fetchOptions = PHFetchOptions()
    let scale = UIScreen.main.scale
    let screenWidth = UIScreen.main.bounds.width * scale
    let screenHeight = UIScreen.main.bounds.height  * scale

    fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate",ascending: false)]
    fetchOptions.predicate = NSPredicate(format: "mediaType = %d || (mediaSubtype & %d) != 0 && (pixelHeight != %d AND pixelWidth != %d) OR (pixelHeight != %d AND pixelWidth != %d)", PHAssetMediaType.image.rawValue, PHAssetMediaSubtype.photoLive.rawValue ,screenHeight, screenWidth, screenWidth, screenHeight)

    let allPhotos = PHAsset.fetchAssets(with: .image, options: fetchOptions)
    allPhotos.enumerateObjects { (asset, index, bool) in
        photosAssets.append(asset)
    }
    completion(photosAssets)
}