PKCanvas 不能作为 PDFKit OverlayView 的子视图绘制

Question

我想在 iPad OS 16 中使用新的 PDFKit OverlayProvider 协议在 PDFView 上自动覆盖铅笔套件画布。我为 PDFKit 添加了 PKCanvas 视图作为 OverlayView 的子视图，即 UIView。 我成功地显示和删除基于 OverlayViewProvider 协议的覆盖视图。 在覆盖提供程序中设置 pdfview

画布按预期显示，但是未激活铅笔交互。 相反，只有 PDF UI 滚动视图手势被激活。 我应该放弃 PDF 视图的手势吗？

用于 Swift UI 的 PDFView

struct PDFKitViewRepresentable: UIViewRepresentable {
    let pdfDocument: PDFDocument
    let pdfView:PDFView
    
    
    init(showing pdfDoc: PDFDocument, pdfView:PDFView) {
        self.pdfDocument = pdfDoc
        self.pdfView = pdfView
    }
    
    func makeUIView(context: Context) -> PDFView {
        
        pdfView.displayDirection = .vertical
        pdfView.displayMode = .singlePageContinuous
        pdfView.usePageViewController(true)
        pdfView.pageBreakMargins = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
        pdfView.autoScales = false
        
        pdfView.delegate = context.coordinator
        pdfView.pageOverlayViewProvider = context.coordinator
        pdfView.backgroundColor = UIColor(white: 0.04, alpha: 0.2)
        
        return pdfView
    }
    
    func updateUIView(_ pdfView: PDFView, context: Context) {
        pdfView.document = pdfDocument
    }
    
    func makeCoordinator()-> Coordinator {
        Coordinator()
    }
}

协调员代码

class Coordinator: NSObject, PDFPageOverlayViewProvider, PDFViewDelegate, PDFDocumentDelegate, UIGestureRecognizerDelegate, PKCanvasViewDelegate, PKToolPickerObserver {
    
    var pageToViewMapping = [PDFPage: CustomUIView]()
    
    func pdfView(_ view: PDFView, overlayViewFor page: PDFPage) -> UIView? {
        var resultView:CustomUIView  = CustomUIView()
        
        if let overlayView = pageToViewMapping[page] {

        var canvas = overlayView.viewWithTag((Int(page.label!)!))
            canvas?.becomeFirstResponder()
            resultView = overlayView
        } else {
            let toolPicker = PKToolPicker.init()
            var canvasView = PKCanvasView(frame: CGRect(x: 0, y: 0, width: 500, height: 500))
            
            resultView.backgroundColor = UIColor.red.withAlphaComponent(0.1)
            canvasView.drawingPolicy = .anyInput

            canvasView.backgroundColor = .yellow.withAlphaComponent(0.2)

            resultView.frame = page.bounds(for: .mediaBox)

            toolPicker.addObserver(canvasView)
            toolPicker.setVisible(true, forFirstResponder: canvasView)
            canvasView.delegate = resultView
            canvasView.becomeFirstResponder()            
            canvasView.tag = Int(page.label!)!
            resultView.addSubview(canvasView)
            pageToViewMapping[page] = resultView
        }
        
        let page = MyPDFPage(page:page)
        return resultView
    }
    
    func pdfView(_ pdfView: PDFView, willDisplayOverlayView overlayView: UIView, for page: PDFPage){                
    // Overlay view will display
    }
    
    func pdfView(_ pdfView: PDFView, willEndDisplayingOverlayView overlayView: UIView, for page: PDFPage){
    // Overlay view would be disappear
    }
    
}

在 2022 WWDC PDFKit 视频 - https://developer.apple.com/videos/play/wwdc2022/10089/ - 只需不到 30 行代码即可实现。 所以我使用代码片段并检查基本机制。 但不能在画布上绘制。

Answer 1

绘图手势和滚动手势冲突的原因是 PDF View 的配置。

pdfView.displayMode =.singlePageContinuous pdfView.usePageViewController(假)

然后您应该在覆盖视图安装时将 isUserInteractionEnabled 设置为 true。

请参阅PDFKit - 带有 PKCanvasView 的 PDFPageOverlayViewProvider 不转发触摸事件 - WWDC22 Session 10089