By setting the PKCanvasView background color to blue, I can tell that the PKCanvasView for each PDFPage is created normally, but it does not respond to touch. Specifically, whether it is finger or applepencil, all the responses of the page occur from PDFView(such as zoom and scroll), and PKCanvasView can not draw, please how to solve? class PDFAnnotatableViewController: UIViewController, PDFViewDelegate { private let pdfView = PDFView() private var pdfDocument: PDFDocument? let file: FileItem private var userSettings: UserSettings @Binding var selectedPage: Int @Binding var currentMode: Mode @Binding var latestPdfChatResponse: LatestPDFChatResponse @State private var pdfPageCoordinator = PDFPageCoordinator() @ObservedObject var userMessage: ChatMessage init(file: FileItem, userSettings: UserSettings, drawDataList: Binding<[DrawDataItem]>, selectedPage: Binding<Int>, currentMode: Binding<Mode>, latestPdfChatResponse: Binding<LatestPDFChatResponse>, userMessage: ChatMessage) { self.file = file self.userSettings = userSettings self._selectedPage = selectedPage self._currentMode = currentMode self._latestPdfChatResponse = latestPdfChatResponse self.userMessage = userMessage super.init(nibName: nil, bundle: nil) DispatchQueue.global(qos: .userInitiated).async { if let document = PDFDocument(url: file.pdfLocalUrl) { DispatchQueue.main.async { self.pdfDocument = document self.pdfView.document = document self.goToPage(selectedPage: selectedPage.wrappedValue - 1) } } } } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } override func viewDidLoad() { super.viewDidLoad() setupPDFView() } private func setupPDFView() { pdfView.delegate = self pdfView.autoScales = true pdfView.displayMode = .singlePage pdfView.displayDirection = .vertical pdfView.backgroundColor = .white pdfView.usePageViewController(true) pdfView.displaysPageBreaks = false pdfView.displaysAsBook = false pdfView.minScaleFactor = 0.8 pdfView.maxScaleFactor = 3.5 pdfView.pageOverlayViewProvider = pdfPageCoordinator if let document = pdfDocument { pdfView.document = document goToPage(selectedPage: selectedPage) } pdfView.frame = view.bounds pdfView.autoresizingMask = [.flexibleWidth, .flexibleHeight] view.addSubview(pdfView) NotificationCenter.default.addObserver( self, selector: #selector(handlePageChange), name: .PDFViewPageChanged, object: pdfView ) } // Dealing with page turning @objc private func handlePageChange(notification: Notification) { guard let currentPage = pdfView.currentPage, let document = pdfView.document else { return } let currentPageIndex = document.index(for: currentPage) if currentPageIndex != selectedPage - 1 { DispatchQueue.main.async { self.selectedPage = currentPageIndex + 1 } } } func goToPage(selectedPage: Int) { guard let document = pdfView.document else { return } if let page = document.page(at: selectedPage) { pdfView.go(to: page) } } // Switch function func togglecurrentMode(currentMode: Mode){ DispatchQueue.main.async { if self.currentMode == .none{ self.pdfView.usePageViewController(true) self.pdfView.isUserInteractionEnabled = true } else if self.currentMode == .annotation { if let page = self.pdfView.currentPage { if let canvasView = self.pdfPageCoordinator.getCanvasView(forPage: page) { canvasView.isUserInteractionEnabled = true canvasView.tool = PKInkingTool(.pen, color: .red, width: 20) canvasView.drawingPolicy = .anyInput canvasView.setNeedsDisplay() } } } } } } class MyPDFPage: PDFPage { var drawing: PKDrawing? func setDrawing(_ drawing: PKDrawing) { self.drawing = drawing } func getDrawing() -> PKDrawing? { return self.drawing } } class PDFPageCoordinator: NSObject, PDFPageOverlayViewProvider { var pageToViewMapping = [PDFPage: PKCanvasView]() func pdfView(_ view: PDFView, overlayViewFor page: PDFPage) -> UIView? { var resultView: PKCanvasView? = nil if let overlayView = pageToViewMapping[page] { resultView = overlayView } else { let canvasView = PKCanvasView(frame: view.bounds) canvasView.drawingPolicy = .anyInput canvasView.tool = PKInkingTool(.pen, color: .systemYellow, width: 20) canvasView.backgroundColor = .blue pageToViewMapping[page] = canvasView resultView = canvasView } if let page = page as? MyPDFPage, let drawing = page.drawing { resultView?.drawing = drawing } return resultView } func pdfView(_ pdfView: PDFView, willEndDisplayingOverlayView overlayView: UIView, for page: PDFPage) { guard let overlayView = overlayView as? PKCanvasView, let page = page as? MyPDFPage else { return } page.drawing = overlayView.drawing pageToViewMapping.removeValue(forKey: page) } func savePDFDocument(_ pdfDocument: PDFDocument) -> Data { for i in 0..<pdfDocument.pageCount { if let page = pdfDocument.page(at: i) as? MyPDFPage, let drawing = page.drawing { let newAnnotation = PDFAnnotation(bounds: drawing.bounds, forType: .stamp, withProperties: nil) let codedData = try! NSKeyedArchiver.archivedData(withRootObject: drawing, requiringSecureCoding: true) newAnnotation.setValue(codedData, forAnnotationKey: PDFAnnotationKey(rawValue: "drawingData")) page.addAnnotation(newAnnotation) } } let options = [PDFDocumentWriteOption.burnInAnnotationsOption: true] if let resultData = pdfDocument.dataRepresentation(options: options) { return resultData } return Data() } func getCanvasView(forPage page: PDFPage) -> PKCanvasView? { return pageToViewMapping[page] } } Is there an error in my code? Please tell me how to make PKCanvasView painting normally?