I am making an app pdf reader using PDFKit but I am unable to get the current page number. I can get the total pages by pdfView.document?.pageCount. The alternative way we can use for this is to change the page by button and count it but I want the PDFView default feature Changing the page by Swipe by sitting the pdfView.usePageViewController(true) but it does not give any method to get the current page number

Code

struct ContentView: View {
    let url = Bundle.main.url(forResource: "file", withExtension: "pdf")
    var body: some View {
        VStack{
            PDFKitRepresentedView(data: try! Data(contentsOf: url!))
        }
    }
}
struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

import PDFKit
import SwiftUI


struct PDFKitRepresentedView: UIViewRepresentable {
    typealias UIViewType = PDFView
    let data: Data
    func makeUIView(context _: UIViewRepresentableContext<PDFKitRepresentedView>) -> UIViewType {
        // Create a `PDFView` and set its `PDFDocument`.
        let pdfView = PDFView(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height))
        pdfView.document = PDFDocument(data: data)
        pdfView.backgroundColor = UIColor.red
        pdfView.displayMode = .singlePage
        pdfView.displayDirection = .horizontal
        pdfView.usePageViewController(true)
        pdfView.maxScaleFactor = pdfView.scaleFactorForSizeToFit
        pdfView.minScaleFactor = pdfView.scaleFactorForSizeToFit
        pdfView.autoScales = true
        
        return pdfView
    }
    func updateUIView(_ pdfView: UIViewType, context _: UIViewRepresentableContext<PDFKitRepresentedView>) {
        pdfView.document = PDFDocument(data: data)
    }
}

CodePudding user response：

According to the docs at: https://developer.apple.com/documentation/pdfkit/pdfview there is a currentPage that returns the current page. You could then use something like this to get the index of it:

if let thePage = pdfView.currentPage, let ndx = pdfView.document?.index(for: thePage) {
   print("--> currentPageIndex: \(ndx) ")
   // ....
}

EDIT-1:

Try the following approach, using a Coordinator class for the PDFViewDelegate and getting notified when a .PDFViewPageChanged with a NotificationCenter.default.addObserver(...).

You will have to adjust the code for your own purpose.

struct PDFKitRepresentedView: UIViewRepresentable {
    typealias UIViewType = PDFView
    let data: Data
    let pdfView = PDFView(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width, height: UIScreen.main.bounds.height))

    func makeUIView(context: Context) -> UIViewType {
        pdfView.document = PDFDocument(data: data)
        pdfView.backgroundColor = UIColor.red
        pdfView.displayMode = .singlePage
        pdfView.displayDirection = .horizontal
        pdfView.usePageViewController(true)
        pdfView.maxScaleFactor = pdfView.scaleFactorForSizeToFit
        pdfView.minScaleFactor = pdfView.scaleFactorForSizeToFit
        pdfView.autoScales = true
        pdfView.delegate = context.coordinator

        return pdfView
    }
    
    func updateUIView(_ pdfView: UIViewType, context _: Context) {
        pdfView.document = PDFDocument(data: data)
    }
    
    func makeCoordinator() -> Coordinator {
        return Coordinator(self)
    }
        
    class Coordinator: NSObject, PDFViewDelegate {
        var parent: PDFKitRepresentedView
        var prevPage = -1
        
        init(_ parent: PDFKitRepresentedView) {
            self.parent = parent
            super.init()
            NotificationCenter.default.addObserver(self, selector: #selector(pageChangeHandler(_:)), name: .PDFViewPageChanged, object: nil)
        }

        @objc func pageChangeHandler(_ notification: Notification) {
            if let thePage = parent.pdfView.currentPage,
                let ndx = parent.pdfView.document?.index(for: thePage), 
                prevPage != ndx {
                print("--------> currentPageIndex: \(ndx) ")
                prevPage = ndx
            }
        }
    }
    
}