如何在我的应用程序中将图像标记为收藏夹

Question

我有一组图像，每个图像在一个集合视图单元格中有三个按钮（保存、收藏、分享）。如何将图像标记为我最喜欢的图像？我想在我的应用程序内的文件夹中显示标记的图像。谢谢！

import Photos 

    @objc func favouriteImage(sender: UIButton) {
            for index in 0..<images.count {
                if sender.tag == index {

                    PHPhotoLibrary.shared().performChanges({
                        let request = PHAssetChangeRequest(forAsset: )
                        request.favorite = true
                    }, completionHandler: { success, error in

                    })

Answer 1

您尝试更新的 PHAsset 是一个不可变对象。请参考下面的link https://developer.apple.com/documentation/photokit/phasset

要将资产标记为私有，您需要在照片更改执行块中创建 PHAssetChange 请求。此信息已在苹果开发者网页上提供。这是苹果文档中指定的代码块 - https://developer.apple.com/documentation/photokit/phassetchangerequest

- (void)toggleFavoriteForAsset:(PHAsset *)asset {
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        // Create a change request from the asset to be modified.
        PHAssetChangeRequest *request = [PHAssetChangeRequest changeRequestForAsset:asset];
        // Set a property of the request to change the asset itself.
        request.favorite = !asset.favorite;

    } completionHandler:^(BOOL success, NSError *error) {
        NSLog(@"Finished updating asset. %@", (success ? @"Success." : error));
    }];
}

Answer 2

我希望您使用自定义单元格来显示图像和单元格中的这 3 个按钮。要将图像标记为收藏，最好的方法是在单元格和 collection 视图之间使用委托。

以下代码将进入您的自定义单元格，例如ImageCollectionViewCell

protocol ImageCollectionViewCellProtocol {
 func didSelect(cell: ImageCollectionViewCell)
}

class ImageCollectionViewCell: UICollectionViewCell {

@IBOutlet weak var favouriteButton: UIButton!

override func awakeFromNib() {
    super.awakeFromNib()        
    let image = UIImage(named: "favourite1.png")
    let imageFilled = UIImage(named: "favourite2.png")
    favouriteButton.setImage(image, for: .normal)
    favouriteButton.setImage(imageFilled, for: .selected)
}

// The IBAction for Favourite button
@IBAction func didTapMakeFavourite(_ sender: Any) {
    guard let cell = (sender as AnyObject).superview?.superview as? ImageCollectionViewCell else {
        return // or fatalError() or whatever
    }

    self.delegate.didSelect(cell: cell)
    favouriteButton.isSelected.toggle()
}
}

以下代码将进入具有 collectionView 实现的视图控制器，例如ImagesCollectionViewController

extension ImagesCollectionViewController: UICollectionViewDataSource {
            func collectionView(_ collectionView: UICollectionView, 
      cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
             ... 
                cell.delegate = self
             ...
            }

    }

extension ImagesCollectionViewController: ImageCollectionViewCellProtocol {
        func didSelect(cell: ImageCollectionViewCell) {
            let indexPath = imagesCollectionView.indexPath(for: cell)
            // do whatever you want with this indexPath's cell 
        }

}

如何在我的应用程序中将图像标记为收藏夹

How do I mark an image as Favorite in my app

ios

swift

uicollectionview

phphotolibrary