UIActivityViewController finishWithItemsHandler 函数未在 MacOS 应用程序中调用

Question

背景

shareImage()下面代码中的函数启动UIActivityViewController并共享图像，例如发送到消息或保存到照片。

图像共享后，UIActivityViewController完成并调用该completionWithItemsHandler函数activityComplete()。

该代码在 iOS / iPadOS / MacOS 上运行良好，符合预期并共享图像，但在 MacOS 上，该completionWithItemsHandler函数activityComplete()永远不会被调用，并使用标志确认print("Share complete.")。

Xcode 会记录以下输出： Scene destruction request failed with error: (null)

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问题

导致该completionWithItemsHandler函数activityComplete()无法在 MacOS 上调用的问题的原因是什么？如何在代码中纠正此问题？

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代码

注意：根据答案添加了两行更新。

import UIKit

class ViewController: UIViewController {

    var shareButton = UIButton(type: UIButton.ButtonType.custom)
    var activityImage: UIImage!

    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Create share button
        shareButton.setTitle("Share", for:UIControl.State())
        shareButton.setTitleColor(.white, for: UIControl.State())
        shareButton.backgroundColor = .purple
        shareButton.frame = CGRect(x: 50, y: 100, width: 200, height: 200)
        shareButton.addTarget(self, action: #selector(ViewController.shareImage), for:.touchUpInside)
        view.addSubview(shareButton)
    }


    private var activity: UIActivityViewController?  // <-- Added
    
    @objc func shareImage() {
        
        // Take view screenshot
        UIGraphicsBeginImageContextWithOptions(self.view.frame.size, false, 0)
        self.view.drawHierarchy(in: CGRect(x: 0, y: 0, width: self.view.bounds.width, height: self.view.bounds.height), afterScreenUpdates: false)
        activityImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        
        // Share view screenshot
        let activity = UIActivityViewController(activityItems: [activityImage as Any], applicationActivities: nil)
        
        // Present iPhone share options
        if UIDevice.current.userInterfaceIdiom == .phone {
            self.present(activity, animated: true, completion: nil)
        }
        
        // Present iPad share options
        if UIDevice.current.userInterfaceIdiom == .pad {
            self.present(activity, animated: true, completion: nil)
            if let popOver = activity.popoverPresentationController {
                popOver.sourceView = self.shareButton
            }
        }
        
        // Complete share
        activity.completionWithItemsHandler = {activity, success, items, error in
            self.activityComplete()
        }

        self.activity = activity  // <-- Added

    }
    
    func activityComplete() {
        
        print("Share complete.")
    }
}

Answer 1

尝试在呈现后保留您的活动视图控制器。就像是：

    private var activityViewController: UIActivityViewController?

    @objc func presentActivityViewController(activityItems: [Any]) {
        let activityViewController = UIActivityViewController(activityItems: activityItems, applicationActivities: nil)
        self.present(activityViewController, animated: true, completion: nil)
        activityViewController.completionWithItemsHandler = { activity, success, items, error in
            // some logic
        }
        self.activityViewController = activityViewController // <- retaining activityViewController
    }