swift - 在 OS X 10.13 上快速拖放邮件

Question

我已经为 Mail 工作了一段时间的拖放工作。直到我升级到 OSX 10.13。

这是我的代码：

class DropView: NSView
{
    var filePath: String?

    required init?(coder: NSCoder) {
        super.init(coder: coder)

        self.wantsLayer = true
        self.layer?.backgroundColor = NSColor.red.cgColor

        registerForDraggedTypes([NSPasteboard.PasteboardType
            .fileNameType(forPathExtension: ".eml"), NSPasteboard.PasteboardType.filePromise])
    }

    override func draggingEntered(_ sender: NSDraggingInfo) -> NSDragOperation {
        if true
        {
            self.layer?.backgroundColor = NSColor.blue.cgColor
            return .copy
        }
    }

     override func draggingExited(_ sender: NSDraggingInfo?)
    {
        self.layer?.backgroundColor = NSColor.red.cgColor
    }

    override func draggingEnded(_ sender: NSDraggingInfo)
    {
        self.layer?.backgroundColor = NSColor.gray.cgColor
    }

    override func performDragOperation(_ sender: NSDraggingInfo) -> Bool
    {
        let pasteboard: NSPasteboard = sender.draggingPasteboard()

        let filePromises = pasteboard.readObjects(forClasses: [NSFilePromiseReceiver.self], options: nil) as? [NSFilePromiseReceiver]

        let folderPath = NSHomeDirectory()+"/Drop Stuff/"
        if (!FileManager.default.fileExists(atPath: folderPath))
        {
            do
            {
                try FileManager.default.createDirectory(atPath: folderPath, withIntermediateDirectories: true, attributes: nil)
            }
            catch
            {
                print ("error")
            }
        }

        let folderURL = NSURL(fileURLWithPath: folderPath)
        let f = sender.namesOfPromisedFilesDropped(atDestination: folderURL as URL)
        print (f!)
        print ("Copied to \(folderPath)")
        return true
    }
}

问题是 namesOfPromisedFilesDropped 返回父文件夹的名称，而不是文件的名称，就像它在以前版本的操作系统上所做的那样。

编译器警告 namesOfPromisedFilesDropped 已弃用。Apple 做得很好，因为它没有提供任何关于新东西的文档。多亏了 StackOverflow，我设法将它拼凑在一起，它可以使用新的 API，但仍然表现出与上述相同的问题。

class DropView2: NSView
{
    var filePath: String?

    required init?(coder: NSCoder) {
        super.init(coder: coder)

        self.wantsLayer = true
        self.layer?.backgroundColor = NSColor.red.cgColor

        registerForDraggedTypes([NSPasteboard.PasteboardType
            .fileNameType(forPathExtension: ".eml"), NSPasteboard.PasteboardType.filePromise])
    }

    override func draggingEntered(_ sender: NSDraggingInfo) -> NSDragOperation {
        if true
        {
            self.layer?.backgroundColor = NSColor.blue.cgColor
            return .copy
        }
    }

    override func draggingExited(_ sender: NSDraggingInfo?)
    {
        self.layer?.backgroundColor = NSColor.red.cgColor
    }

    override func draggingEnded(_ sender: NSDraggingInfo)
    {
        self.layer?.backgroundColor = NSColor.gray.cgColor
    }

    override func performDragOperation(_ sender: NSDraggingInfo) -> Bool
    {

        let pasteboard: NSPasteboard = sender.draggingPasteboard()

        guard let filePromises = pasteboard.readObjects(forClasses: [NSFilePromiseReceiver.self], options: nil) as? [NSFilePromiseReceiver] else {
            return false
        }

        print ("Files dropped")
        var files = [URL]()

        let filePromiseGroup = DispatchGroup()
        let operationQueue = OperationQueue()
        let destURL = URL(fileURLWithPath: "/Users/andrew/Temporary", isDirectory: true)
        print ("Destination URL: \(destURL)")

        filePromises.forEach ({ filePromiseReceiver in
            print (filePromiseReceiver)
            filePromiseGroup.enter()

            filePromiseReceiver.receivePromisedFiles(atDestination: destURL,
                                                     options: [:],
                                                     operationQueue: operationQueue,
                                                     reader:
                { (url, error) in
                    print ("Received URL: \(url)")
                    if let error = error
                    {
                        print ("Error: \(error)")
                    }
                    else
                    {
                        files.append(url)
                    }
                    print (filePromiseReceiver.fileNames, filePromiseReceiver.fileTypes)

                    filePromiseGroup.leave()
            })
        })

        filePromiseGroup.notify(queue: DispatchQueue.main,
                                execute:
            {
                print ("Files: \(files)")
                print ("Done")
        })
        return true
    }
}

我正在使用 10.13.2。我做错了什么还是这是一个错误？

它快把我逼疯了。