如何使用 collectionview 将高质量图像发送到另一个视图

Posted 2023-02-23

【中文标题】如何使用 collectionview 将高质量图像发送到另一个视图

【英文标题】：How to send high quality images to another view using collectionview

【发布时间】：2018-10-05 21:52:24

【问题描述】：

我的问题很简单。我有一个collectionView，我正在将图像从它发送到另一个视图并显示它。但问题是质量真的很差。我使用 youtube 上的教程从照片库制作了 collectionView。这是我发送图像的代码。

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) 

    let selectedCell = collectionView.cellForItem(at: indexPath) as! CollectionViewCell
    ujaj = selectedCell.imageView.image
    performSegue(withIdentifier: "segue077", sender: self)

还有我的完整代码：

导入 UIKit 导入照片 类 ViewController：UIViewController，UICollectionViewDelegate，UICollectionViewDataSource，UICollectionViewDelegateFlowLayout @IBOutlet public var bandau：UIImageView！

var imageArray = [UIImage]()

override func viewDidLoad() 
    grabPhotos()


func grabPhotos()

    let imgManager = PHImageManager.default()

    let requestOptions = PHImageRequestOptions()
    requestOptions.isSynchronous = true
    requestOptions.deliveryMode = .highQualityFormat // Quality of images

    let fetchOptions = PHFetchOptions()
    fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]

    if let fetchResult : PHFetchResult = PHAsset.fetchAssets(with: .image, options: fetchOptions) 

        if fetchResult.count > 0 
            for i in 0..<fetchResult.count 
                imgManager.requestImage(for: fetchResult.object(at: i) as! PHAsset, targetSize: CGSize(width: 200, height: 200), contentMode: .aspectFill, options: requestOptions, resultHandler: 
                    image, error in
                    self.imageArray.append(image!)

                )
            
        
        else 
            print("You got no photos")
           //self.collectionView?.reloadData()
        
    



@IBOutlet weak var fakk: UIImageView!

func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int 
    return imageArray.count


func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell 


    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "Cell", for: indexPath) as! CollectionViewCell

    let imageView = cell.viewWithTag(1) as! UIImageView




    imageView.image = imageArray[indexPath.row]



    return cell



public var ujaj: UIImage?


@IBAction func kadsasd(_ sender: Any) 
    performSegue(withIdentifier: "segue077", sender: self)


func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) 

    let selectedCell = collectionView.cellForItem(at: indexPath) as! CollectionViewCell
    ujaj = selectedCell.imageView.image
    performSegue(withIdentifier: "segue077", sender: self)



func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize 
    let width = collectionView.frame.width / 3 - 1

    return CGSize(width: width, height: width)


func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat 
    return 1.0

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat 
    return 1.0




override func prepare(for segue: UIStoryboardSegue, sender: Any?) 
    let main = segue.destination as! display



    main.image = ujaj

问题是如何发送完整质量的图像？因为现在我有 200x200 的照片。如果我更改为更高，那么我的应用程序会因为内存而自动崩溃。当用户点击单元格时，也许可以获得完整质量的图像？

【参考方案1】：

只要您有 indexPath，我建议您将其转换为 Integer，然后再次从库中请求照片。不要忘记将 .targetSize 更改为 PHImageManagerMaximumSize 也将 .contentMode 更改为 PHImageContentMode.default

在你的情况下：

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) 




    let index : Int = indexPath.row


    let imgManager = PHImageManager.default()

    let requestOptions = PHImageRequestOptions()
    requestOptions.isSynchronous = true
    requestOptions.deliveryMode = .highQualityFormat // Quality of images

    let fetchOptions = PHFetchOptions()
    fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]


    let fetchResult : PHFetchResult = PHAsset.fetchAssets(with: .image, options: fetchOptions)

        imgManager.requestImage(for: fetchResult.object(at: index) , targetSize: PHImageManagerMaximumSize, contentMode: PHImageContentMode.default, options: requestOptions, resultHandler: 
            image, error in
            self.ujaj = image

        )

    performSegue(withIdentifier: "segue077", sender: self)