仅获取PHAssetMediaTypeImage类型的照片,表单资产集合类型PHAssetCollectionTypeSmartAlbum

Question

我正在使用Photos框架来获取iOS8中的专辑列表.我能够使用它

PHFetchResult *smartAlbums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];

这给了我所有智能相册的列表,包括视频.如何过滤此列表中的视频.我只需要图像.

帮助将不胜感激.谢谢.

Answer 1

您应该设置提取选项,它有一个属性predicate,可用于过滤视频.以下是这样做的一个例子.

PHFetchResult *smartAlbums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];

//set up fetch options, mediaType is image.
PHFetchOptions *options = [[PHFetchOptions alloc] init];
options.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:NO]];
options.predicate = [NSPredicate predicateWithFormat:@"mediaType = %d",PHAssetMediaTypeImage];

for (NSInteger i =0; i < smartAlbums.count; i++) {
    PHAssetCollection *assetCollection = smartAlbums[i];
    PHFetchResult *assetsFetchResult = [PHAsset fetchAssetsInAssetCollection:assetCollection options:options];

    NSLog(@"sub album title is %@, count is %ld", assetCollection.localizedTitle, assetsFetchResult.count);
    if (assetsFetchResult.count > 0) {
        for (PHAsset *asset in assetsFetchResult) {
            //you have got your image type asset.
        }
    }
}

Answer 2

在swift中做同样的事情:

let fetchOptions = PHFetchOptions()
fetchOptions.predicate = NSPredicate(format: "mediaType = %d", PHAssetMediaType.Image.rawValue)