Swift 在 CollectionView 中结合 PHAsset 和 UIImage

Posted 2023-03-08

【中文标题】Swift 在 CollectionView 中结合 PHAsset 和 UIImage

【英文标题】：Swift combine PHAsset and UIImage in CollectionView

【发布时间】：2018-10-10 12:38:19

【问题描述】：

我需要在UICOllectionView 中合并PHAsset 和UIImage

UIImage 从字符串中获取并转换为图像

从设备相册获取PHAsset

var assetCollection: PHAssetCollection!
var photosAsset: PHFetchResult<AnyObject>!
var assetThumbnailSize: CGSize!
var downloadImages: [String] = []

在 cellForItemAt 我尝试：

    let indexP = indexPath.row

    let asset: PHAsset = self.photosAsset[indexP] as! PHAsset

    PHImageManager.default().requestImage(for: asset, targetSize: self.assetThumbnailSize, contentMode: .aspectFill, options: nil, resultHandler: (result, info)in
    if result != nil 
    let download = self.downloadImages[indexP]
    let downloadIm = "http://...\(download)"

     cell.albumImage.downloadImage(from: downloadIm)

     cell.albumImage.image = result


)
return cell

如何结合 downloadIm 和 result 在 collectionView 上的 UIImageView 中显示？

下载图片是：

extension UIImageView 

    func downloadImage(from imgURL: String!) 
        let url = URLRequest(url: URL(string: imgURL)!)

        let task = URLSession.shared.dataTask(with: url) 
            (data, response, error) in

            if error != nil 
                print(error!)
                return
            

            DispatchQueue.main.async 
                self.image = UIImage(data: data!)
            

        

        task.resume()
    

【问题讨论】：

请澄清您的问题。什么是“结合 PHAsset 和 UIImage”？

@Ilya Kharabet，需要将所有来自 downloadIm(UIImage) 和所有来自 result(PHAsset) 的内容添加到 UICollectioView 中

【参考方案1】：

我在我的一个项目中面临同样的问题。需要在同一个 UICollectionView 中同时处理 UIImage 和字符串 url。你可以实现类似的；

// first create struct with datatypes
struct imageItem 
    var stringImageURL:String 
    var imageGallery:UIImage

var array_ImagesList: [imageItem] = []

// 然后你可以根据功能在任何你想要的地方附加图像或字符串 url // 在 UIImagePickerController Delegates 里面我追加 UIImage

func imagePickerController(_ picker: UIImagePickerController, 
  didFinishPickingMediaWithInfo info: [String : Any]) 

    if let image = info[UIImagePickerControllerOriginalImage] as? UIImage
    
        array_ImagesList.append(imageItem.init(stringImageURL: "", 
        imageGallery: image))
    
   picker.dismiss(animated: true, completion: nil);
 

// and in some other function I want to append image from server URL

func addImagesFromServer() 
let imageUrl: String = "htps://someserver/image.png"
 array_ImagesList.append(imageItem.init(stringImageURL: imageUrl!, 
 imageGallery:""))

 collectionView.reloadData()


//MARK: CollectionView DataSources & Delegates
func collectionView(_ collectionView: UICollectionView, 
   numberOfItemsInSection section: Int) -> Int 
    return array_ImagesList.count


func collectionView(_ collectionView: UICollectionView, cellForItemAt 
    indexPath: IndexPath) -> UICollectionViewCell
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: 
      "kGalleryImageCell", for: indexPath as IndexPath) as! 
     AddImagesCollectionViewCell
    //  check to show image or from url here
      // for image
       cell.imageView.image = array_ImagesList[indexPath.row].imageGallery
      // from image url
                let stringUrlImage = 
                    array_ImagesList[indexPath.row].stringImageURL
                let placeholderImage = UIImage(named: 
                "logoCategorySmallIcon")!
                if(stringUrlImage.isEmpty)
                    cell.imageGalleryCell.image = placeholderImage

                else
                    var stringImageUrl = imageHostAPI+"\(stringUrlImage)"
                    stringImageUrl = 
             stringImageUrl.addingPercentEncoding(withAllowedCharacters: 
            CharacterSet.urlQueryAllowed)!
                    let url = URL(string: stringImageUrl)

                    cell.imageView.sd_setShowActivityIndicatorView(true)
                    cell.imageView.sd_setIndicatorStyle(.gray)
                    cell.imageView.sd_setImage(with: url!, 
                   placeholderImage: placeholderImage)
                

          return cell