如何将PDFPageOverlayViewProvider设置为PDFView？

Question

更新后，我试图为一个pageOverlayViewProvider设置一个PDFView，但它不像预期的那样工作。没有调用PDFPageOverlayViewProvider方法，PDFViewDelegate方法运行良好。

struct ReaderView: UIViewRepresentable {
    
    public typealias UIViewType = PDFView
    
    let url: URL
    let document: PDFDocument
    
    init(_ url: URL) {
        self.url = url
        self.document = PDFDocument(url: self.url)!
    }
    
    func makeCoordinator() -> Coordinator {
        Coordinator()
    }
    
    func makeUIView(context: Context) -> PDFView {
        let pdfView = PDFView()
        
        pdfView.document = document
        pdfView.displayMode = .singlePageContinuous
        pdfView.displayDirection = .vertical
        pdfView.autoScales = true
        pdfView.delegate = context.coordinator
        pdfView.pageOverlayViewProvider = context.coordinator
        pdfView.usePageViewController(true)
        pdfView.backgroundColor = .clear
        
        document.delegate = context.coordinator

        return pdfView
    }
    
    func updateUIView(_ uiView: PDFView, context: Context) {

    }
}

extension ReaderView {
    
    class Coordinator: NSObject, PDFPageOverlayViewProvider, PDFViewDelegate, PDFDocumentDelegate {
        
        func pdfView(_ view: PDFView, overlayViewFor page: PDFPage) -> UIView? {
            return UIView(frame: .zero)
        }
        
        func pdfView(_ pdfView: PDFView, willDisplayOverlayView overlayView: UIView, for page: PDFPage) { 
        }
        
        func pdfView(_ pdfView: PDFView, willEndDisplayingOverlayView overlayView: UIView, for page: PDFPage) { 
        }
        
        func pdfViewWillClick(onLink sender: PDFView, with url: URL) {
        }
        
        func didMatchString(_ instance: PDFSelection) {
        }

}

Answer 1

要使pageOverlayViewProvider与PDFView一起工作，似乎必须在将PDF文档与PDFView关联之前设置该实例属性。

在使用UIViewRepresentable时，当使用makeUIView函数生成PDFView时，以下内容应该可以工作：

func makeUIView(context: Context) -> PDFView {
    let pdfView = PDFView()
    
    pdfView.displayMode = .singlePageContinuous
    pdfView.displayDirection = .vertical
    pdfView.autoScales = true
    pdfView.delegate = context.coordinator
    pdfView.pageOverlayViewProvider = context.coordinator
    pdfView.usePageViewController(true)
    pdfView.backgroundColor = .clear
    
    pdfView.document = document
    document.delegate = context.coordinator

    return pdfView
}