如何获取 swift 中的相册标题、图像数？

Question

我正在构建类似于 iOS 标准照片应用程序的图库应用程序。 (Swift 4.1)

我想获取启动标准照片应用程序时可以看到的缩略图、标题和图像总数。

照片框架似乎比我想象的要复杂。

很难找到解释原因的方法，以及应该处理什么程序。

你能告诉我这件事吗？

Answer 1

达到您要求的最少步数是：

  // import the framework
  import Photos

  // get the albums list
  let albumList = PHAssetCollection.fetchAssetCollections(with: .album, subtype: .albumRegular, options: nil)

  // you can access the number of albums with
  albumList.count
  // individual objects with
  let album = albumList.object(at: 0)
  // eg. get the name of the album
  album.localizedTitle

  // get the assets in a collection
  func getAssets(fromCollection collection: PHAssetCollection) -> PHFetchResult<PHAsset> {
    let photosOptions = PHFetchOptions()
    photosOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: true)]
    photosOptions.predicate = NSPredicate(format: "mediaType == %d", PHAssetMediaType.image.rawValue)

    return PHAsset.fetchAssets(in: collection, options: photosOptions)
  }

  // eg.
  albumList.enumerateObjects { (coll, _, _) in
        let result = self.getAssets(fromCollection: coll)
        print("\(coll.localizedTitle): \(result.count)")
    }

  // Now you can:
  // access the count of assets in the PHFetchResult
  result.count

 // get an asset (eg. in a UITableView)
 let asset = result.object(at: indexPath.row)

 // get the "real" image
 PHCachingImageManager.default().requestImage(for: asset, targetSize: CGSize(width: 200, height: 200), contentMode: .aspectFill, options: nil) { (image, _) in
        // do something with the image
    }

我也建议看看Apple sample code for the Photos framework, is not hard to follow, together with the Photos framework documentation。

如何获取 swift 中的相册标题、图像数？

How to fetch photos album title, image count in swift?

photos

ios