ios - 如何在 PDFKit 中显示从互联网下载的 pdf？

Question

我已经成功地从网上下载了 pdf 文件，它保存在 documents 目录中。下载文件的url如下

file:///Users/heetshah/Library/Developer/CoreSimulator/Devices/4BF83AAF-A910-46EB-AE76-91BC6BEED033/data/Containers/Data/Application/B4532805-2842-431F-B16C-C5E448C8366F/Documents/TPAFForm.pdf

我正在尝试按如下方式将其显示到 PDFKit。

let path = URL(fileURLWithPath: pdfUrl!)
if let document = PDFDocument(url: path) {
  pdfView.document = document
  pdfView.displayMode = .singlePageContinuous
  pdfView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
  pdfView.displaysAsBook = true
  pdfView.displayDirection = .vertical
  pdfView.autoScales = true
  pdfView.maxScaleFactor = 4.0
  pdfView.minScaleFactor = pdfView.scaleFactorForSizeToFit
}

我没有收到任何错误

我浏览了一堆堆栈溢出帖子，它显示的解决方案与上面相同，但它不适用于我的情况。我也尝试了以下解决方案，但它不起作用

if let path = Bundle.main.path(forResource: pdfUrl, ofType: "pdf") {
            let url = URL(fileURLWithPath: path)
            if let pdfDocument = PDFDocument(url: url) {..

以下是我下载文件的代码

func downloadPDF(pdfUrl: String?,fileName: String,completionHandler:@escaping(String,Bool) -> ()){
        let destinationPath: DownloadRequest.DownloadFileDestination = {
            _,_ in
            let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
            let fileURL = documentsURL.appendingPathComponent("\(fileName).pdf")
            return (fileURL,[.removePreviousFile,.createIntermediateDirectories])
        }

        if let pdfUrl = pdfUrl {
            Alamofire.download(pdfUrl, to: destinationPath).downloadProgress { (progress) in

            }.responseData { (response) in
                switch response.result{
                case .success:
                    if response.destinationURL != nil,let filePath = response.destinationURL?.absoluteString{
                        completionHandler(filePath,true)
                    }
                    break
                case .failure:
                    completionHandler("Something went wrong",false)
                    break
                }
            }
        }
    }

我正在使用 Alamofire 下载文件。我的 PDFView 的约束是正确的，因为我能够在预览中显示在线 url pdf，但我需要先在本地下载 pdf，然后在我的 pdf View 中显示它

Answer 1

由于您没有显示足够的代码来调试问题，这里是完整代码来执行您描述的操作，您可以通过将您的代码与我的:

import UIKit
import PDFKit

class ViewController: UIViewController {

    let pdfurl = URL(string:"https://www.apeth.com/rez/release.pdf")!
    let pdffileurl : URL = {
        let fm = FileManager.default
        let docsurl = try! fm.url(
            for: .documentDirectory, in: .userDomainMask, 
            appropriateFor: nil, create: true)
        return docsurl.appendingPathComponent("mypdf.pdf")
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        let sess = URLSession.shared
        sess.downloadTask(with: self.pdfurl) { (url, resp, err) in
            if let url = url {
                let fm = FileManager.default
                try? fm.removeItem(at: self.pdffileurl)
                try? fm.moveItem(at: url, to: self.pdffileurl)
                DispatchQueue.main.async {
                    self.displayPDF()
                }
            }
        }.resume()
    }

    func displayPDF() {
        let pdfview = PDFView(frame:self.view.bounds)
        pdfview.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        pdfview.autoScales = true
        self.view.addSubview(pdfview)
        let doc = PDFDocument(url: self.pdffileurl)
        pdfview.document = doc
    }

}