将图像从 PHAsset 加载到 Imageview

Question

我是 Swift 的新人。在下面的代码中，它检索照片并将它们放入一个数组中。现在我想在图像视图中显示它们。我该怎么做？

我的意思是，例如，如何在图像视图中显示数组的元素。

var list :[PHAsset] = []
PHPhotoLibrary.requestAuthorization { (status) in
    switch status
    {
    case .authorized:
        print("Good to proceed")
        let fetchOptions = PHFetchOptions()
        let allPhotos = PHAsset.fetchAssets(with: .image, options: fetchOptions)
        print(allPhotos.count)
        allPhotos.enumerateObjects({ (object, count, stop) in
            list.append(object)
        })

        print("Found \(allPhotos.count) images")
    case .denied, .restricted:
        print("Not allowed")
    case .notDetermined:
        print("Not determined yet")
    }

另一个问题是：当我调用这个函数时，它似乎是异步执行的。我的意思是调用函数后的代码行将提前执行。这是因为 requestAuthorization 吗？

Answer 1

试试这个：imageView.image = convertImageFromAsset(list[0])

func convertImageFromAsset(asset: PHAsset) -> UIImage {
    let manager = PHImageManager.default()
    let option = PHImageRequestOptions()
    var image = UIImage()
    option.isSynchronous = true
    manager.requestImage(for: asset, targetSize: PHImageManagerMaximumSize, contentMode: .aspectFit, options: option, resultHandler: {(result, info)->Void in
        image = result!
    })
    return image
}

希望对您有所帮助。

Answer 2

你可以这样做:-

创建一个 PHAsset 类型的空数组：-

fileprivate var imageAssets = [PHAsset]()

通过调用此函数获取所有图像:-

func fetchGallaryResources(){
        let status = PHPhotoLibrary.authorizationStatus()
        if (status == .denied || status == .restricted) {
            self.showAlert(cancelTitle: nil, buttonTitles:["OK"], title: "Oops", message:"Access to PHPhoto library is denied.")
            return
        }else{
        PHPhotoLibrary.requestAuthorization { (authStatus) in
            if authStatus == .authorized{
                let imageAsset = PHAsset.fetchAssets(with: .image, options: nil)
                for index in 0..<imageAsset.count{
                    self.imageAssets.append((imageAsset[index]))
                }  
        }

    }

请求图像像这样:-

let availableWidth = UIScreen.main.bounds.size.width
let availableHeight = UIScreen.main.bounds.size.height

循环或单个从 imageAssets 中取出图像 :-

PHImageManager.default().requestImage(for: imageAssets[0], targetSize: CGSize(width : availableWidth, height : calculatedCellWidth), contentMode: .default, options: nil, resultHandler: { (image, info) in
      requestedImageView.image = image

  })

将图像从 PHAsset 加载到 Imageview

Load Images From PHAsset into an Imageview

ios

swift

phasset