ios - Action Extension，在 Instant Markup 中获取图像返回空白屏幕

Question

背景 我有一个可用于图像的 Action 扩展:

class ActionViewController: UIViewController {

    @IBOutlet weak var imageView: UIImageView!

    override func viewDidLoad() {
        super.viewDidLoad()
        var imageFound = false
        for item in self.extensionContext!.inputItems as! [NSExtensionItem] {
            for provider in item.attachments! {
                if provider.hasItemConformingToTypeIdentifier(kUTTypeImage as String) {
                    weak var weakImageView = self.imageView
                    provider.loadItem(forTypeIdentifier: kUTTypeImage as String, options: nil, completionHandler: { (imageURL, error) in
                        OperationQueue.main.addOperation {
                            if let strongImageView = weakImageView {
                                if let imageURL = imageURL as? URL {
                                    strongImageView.image = UIImage(data: try! Data(contentsOf: imageURL))
                                }
                            }
                        }
                    })

                    imageFound = true
                    break
                }
            }
            if (imageFound) {
                break
            }
        }
    }

以上代码是创建 Action 扩展时的默认代码。如果我在 Photos app > Select an image > Share > My Action Extension 中，上面的代码会正确执行。然后图像显示在我的 Action Extension 的 UIImageView 中。 但是当我截取屏幕截图并按下共享按钮(例如，见下图)时，与我的 Action Extension 共享图像会返回一个空白屏幕，控制台中没有任何错误。这同样发生在其他应用程序上。我注意到可以通过即时标记工具进行共享，因为我可以使用 Gmail 共享图像。

以下是我的Info.plist:

<key>NSExtensionActivationRule</key>
    <string>SUBQUERY (
        extensionItems,
        $extensionItem,
        SUBQUERY (
            $extensionItem.attachments,
            $attachment,
            ANY $attachment.registeredTypeIdentifiers UTI-CONFORMS-TO "public.item" ||
            ANY $attachment.registeredTypeIdentifiers UTI-CONFORMS-TO "public.content"
            ).@count == $extensionItem.attachments.@count
            ).@count > 0
    </string>

问题:我不完全确定如何从即时标记工具(内置 iOS 屏幕截图工具)中获取图像。

Answer 1

我使用以下链接弄明白了:ios swift share-extension: what are all and the best ways to handle images?

问题是什么？

问题是，因为当您从 Photos 加载图像时，图像是 URL 类型，而从 Screenshot 工具加载图像时，图像是 UIImage 类型。因此，有必要针对不同的情况明确处理数据加载。

我是这样实现的:

if let content = extensionContext!.inputItems[0] as? NSExtensionItem {
    let contentType = kUTTypeImage as String
    if (content.attachments) != nil {
        for attachment in content.attachments! {
            if attachment.hasItemConformingToTypeIdentifier(contentType as String) {
                attachment.loadItem(forTypeIdentifier: contentType as String, options: nil) { data, error in
                    if error == nil {
                        var contentData: Data? = nil

                        // Handling if image data is raw data.
                        if let data = data as? Data {
                            contentData = data

                            // Handling if image data is an URL.
                        } else if let url = data as? URL {
                            contentData = try? Data(contentsOf: url)
                        }

                            // Handling if image data is an UIImage object, for example from the Screenshot tool.
                        else if let imageData = data as? UIImage {
                            contentData = imageData.pngData()
                        }

                        // Proceed here with contentData.
                        self.imageView.image = UIImage(data: contentData!)
                    }
                }
            }
        }
    }
}

完成 T̶O̶D̶O̶ C̶u̶r̶r̶e̶n̶t̶l̶y̶̶t̶h̶e̶r̶e̶̶i̶s̶̶a̶̶s̶i̶g̶n̶i̶f̶i̶c̶a̶n̶t̶̶d̶e̶l̶a̶y̶̶w̶h ̶e̶n̶̶l̶o̶a̶d̶i̶n̶g̶̶a̶n̶̶i̶m̶a̶g̶e̶̶f̶r̶o̶m̶̶S̶c̶r̶e̶e̶n̶s̶h̶o̶t̶̶t̶o̶o̶l̶ ̶i̶n̶t̶o̶̶m̶y̶̶e̶x̶t̶e̶n̶s̶i̶o̶n̶。̶̶H̶o̶w̶e̶v̶e̶r̶,̶̶t̶h̶i̶s̶̶i̶s̶s̶u̶e̶̶i̶s ̶ o̶u̶t̶̶o̶f̶̶c̶o̶n̶t̶e̶x̶t̶̶o̶f̶̶w̶h̶a̶t̶̶I̶̶o̶r̶i̶g̶i̶n̶a̶l̶l̶y̶̶a̶s̶k̶e ̶d̶̶s̶o̶̶I̶̶w̶i̶l̶l̶̶m̶a̶r̶k̶̶t̶h̶i̶s̶̶q̶u̶e̶s̶t̶i̶o̶n̶̶a̶s̶̶s̶o̶l̶v̶e̶d̶。 ̶ ̶I̶f̶̶I̶̶f̶i̶n̶d̶̶a̶̶s̶o̶l̶u̶t̶i̶o̶n̶̶t̶o̶̶t̶h̶e̶̶s̶l̶o̶w̶n̶e̶s̶s̶ ̶I̶̶c̶a̶n̶̶m̶a̶y̶b̶e̶̶a̶d̶d̶̶i̶t̶̶h̶e̶r̶e̶̶a̶s̶̶a̶̶c̶o̶m̶m̶e̶n̶t̶。̶

延迟可以通过将图像加载到不同的线程来解决(据我所知):

var imageFound = false
for item in self.extensionContext!.inputItems as! [NSExtensionItem] {
    for provider in item.attachments! {
        if provider.hasItemConformingToTypeIdentifier(kUTTypeData as String) {
            weak var weakImageView = self.imageView
            provider.loadItem(forTypeIdentifier: kUTTypeData as String, options: nil, completionHandler: { (data, error) in
                DispatchQueue.main.async {
                    if let strongImageView = weakImageView {
                        var contentData: Data? = nil
                        // Handling if image data is raw data.
                        if let data = data as? Data {
                            contentData = data
                            strongImageView.image = UIImage(data: contentData!)
                        // Handling if image data is an URL.
                        } else if let url = data as? URL {
                            contentData = try? Data(contentsOf: url)
                            strongImageView.image = UIImage(data: contentData!)
                        }
                        // Handling if image data is an UIImage object, for example from the Screenshot tool.
                        else if let imageData = data as? UIImage {
                            contentData = imageData.pngData()
                            strongImageView.image = UIImage(data: contentData!)
                        }
                    }
                }
            })
            imageFound = true
            break
        }
    }
    if (imageFound) {
        break
    }
}