Question

我正在尝试使用其网址在另一个视图中显示本地库中的图像，如此...

let myImgObj = messagesFromTheDisk[indexPath.row].images

print(myImgObj)
print(myImgObj[0].url)

打印myImgObj提供[MyApp.ProductImage(url: assets-library://asset/asset.PNG?id=A636DA16-8C7C-4CC5-ADB3-E944DC24BDA1&ext=PNG)]，打印myImgObj[0].url提供assets-library://asset/asset.PNG?id=A636DA16-8C7C-4CC5-ADB3-E944DC24BDA1&ext=PNG

但是当我尝试显示此图像时，它显示为null虽然似乎有一个网址。我正在使用库SDWebImage来显示图像......

cell.productImageView.sd_setImage(with: myImgObj[0].url, placeholderImage:UIImage(named: "sampleImg"))

我做错了什么......？

Answer 1

这没有SDWebImage，因为我不需要PHAssets。我从我的自定义相册中获取库中的assests：

    func fetchCustomAlbumPhotos( completion : (_ array : [PHAsset]) -> Void)
        {
            var assetCollection          = PHAssetCollection()
            var photoAssets              = PHFetchResult<AnyObject>()
            var arrayOfPHAsset           = [PHAsset]()
            let fetchOptions             = PHFetchOptions()
            fetchOptions.predicate       = NSPredicate(format: "title = %@", CustomAlbum.albumName)
            let collection:PHFetchResult = PHAssetCollection.fetchAssetCollections(with: .album, subtype: .any, options: fetchOptions)

            if let _:AnyObject = collection.firstObject{
                assetCollection = collection.firstObject!
            }else {
                completion([])
            }
            _           = collection.count
            photoAssets = PHAsset.fetchAssets(in: assetCollection, options: nil) as! PHFetchResult<AnyObject>
            photoAssets.enumerateObjects({(object: AnyObject!,
                count: Int,
                stop: UnsafeMutablePointer<ObjCBool>) in

                if object is PHAsset{
                    let asset = object as! PHAsset
                    arrayOfPHAsset.append(asset)
                }
            })
            completion(arrayOfPHAsset)


}

这是我在ViewController的viewDidLoad（）方法中调用它的方式：

CustomAlbum().fetchCustomAlbumPhotos { (array) in
                self.arrayOfPHAsset = array

                self.collectionView.reloadData()
            }

从该函数我得到arrayOfPHAsset，这就是我在我的集合视图中显示它们的方法：cellForItemAt方法：

let asset : PHAsset = arrayOfPHAsset[indexPath.item]

或将您的网址转换为PHAsset

self.imageURL = (info[UIImagePickerControllerReferenceURL] as? NSURL)!
let asset = PHAsset.fetchAssetsWithALAssetURLs([imageUrl], options: nil).firstObject as! PHAsset

请求该PHAsset的图像

        if asset.mediaType == .video{
            cell.videoIndicatorImage.isHidden = false
        }

        cell.userImagesStoredInAlbum.alpha = 0
        let imageSize = CGSize(width: asset.pixelWidth,height: asset.pixelHeight)
        DispatchQueue.main.async {
            PHImageManager.default().requestImage(for: asset, targetSize: imageSize, contentMode: .aspectFill, options: nil, resultHandler: {(result, info)in
                if result != nil {
                    cell.userImagesStoredInAlbum.image = result
                    UIView .animate(withDuration: 0.5, delay: 0, options: .curveEaseIn, animations: {
                        cell.userImagesStoredInAlbum.alpha = 1
                    }, completion: { (succes) in

                    })
                }
            })
        }

Answer 2

我设置图片libary url nil并使用contentsOfFile来捕获磁盘中的图像，以便立即加载图像并且它可以正常工作。但是你必须将图像放在.xcassettes文件夹中而是单独的一组文件夹中。

let bundlePath = Bundle.main.path(forResource: myImgObj, ofType: "jpg") 
imageView.sd_setImage(with: nil, placeholderImage: UIImage(contentsOfFile: bundlePath!))

从本地图书馆传递图像的网址

2 个答案: