import Cocoa @available(macOS 10.13, *) let imagePboardType = NSPasteboard.PasteboardType.fileURL class DragSourceView: NSImageView { weak var dragSourceDelegate: NSDraggingSource? override func mouseDown(with event: NSEvent) { //拖放数据定义 let pasteboardItem = NSPasteboardItem() //设置数据的Provider if #available(macOS 10.13, *) { pasteboardItem.setDataProvider(self, forTypes: [NSPasteboard.PasteboardType.fileURL]) } else { // Fallback on earlier versions } //拖放item let draggingItem = NSDraggingItem(pasteboardWriter: pasteboardItem) draggingItem.draggingFrame = NSRect(x: 100 , y: 10, width: 100, height: 100) //拖放可视化图象设置 draggingItem.imageComponentsProvider = { let component = NSDraggingImageComponent(key: NSDraggingItem.ImageComponentKey.icon) component.frame = NSRect(x: 0, y: 0, width: 16, height: 16) component.contents = NSImage(size: NSSize(width: 32,height: 32), flipped: false, drawingHandler: { [unowned self] rect in { self.image?.draw(in: rect) return true }() } ) return [component] } //开始启动拖放sesson self.beginDraggingSession(with: [draggingItem], event: event, source: self.dragSourceDelegate!) } } extension DragSourceView: NSPasteboardItemDataProvider { func pasteboard(_ pasteboard: NSPasteboard?, item: NSPasteboardItem, provideDataForType type: NSPasteboard.PasteboardType) { // let data = self.image?.tiffRepresentation let data = "/Users/slowdony/Desktop/640.jpeg" let dataUrl = data.data(using: String.Encoding(rawValue: NSUTF8StringEncoding))! item.setData(dataUrl, forType: type) } } import Cocoa class ViewController: NSViewController { @IBOutlet weak var sourceView: DragSourceView! override func viewDidLoad() { super.viewDidLoad() self.sourceView.dragSourceDelegate = self } } extension ViewController: NSDraggingSource { //返回拖放操作类型 func draggingSession(_ session: NSDraggingSession, sourceOperationMaskFor context: NSDraggingContext) -> NSDragOperation { if (context == .outsideApplication){ return .copy } else{ return .generic } } //开始拖放代理回调 func draggingSession(_ session: NSDraggingSession, willBeginAt screenPoint: NSPoint) { print("draggingSession beginAt \(screenPoint)") } //拖放鼠标移动时的代理回调 func draggingSession(_ session: NSDraggingSession, movedTo screenPoint: NSPoint) { print("draggingSession movedTo \(screenPoint)") } //结束拖放代理回调 func draggingSession(_ session: NSDraggingSession, endedAt screenPoint: NSPoint, operation: NSDragOperation) { print("draggingSession endedAt \(screenPoint)") } } I am dragging an image to the desktop through the above code, failed, help